Answer:
Secondary SchoolPhysics 5+3 ptsA body starts from rest and moves with a uniform acceleration.
A wheel has an angular speed of 32 rev/s when it experiences a constant angular acceleration of 65 rev/s2 which causes it to spin FASTER. During this time the wheel completes 92 rev. Determine how long the wheel was experiencing this angular acceleration and how fast the wheel was spinning at the end of this period. Assume that the wheel doesn't change the direction of its spin.
Answer:
ωf = 113.95 rev/s
t = 1.26 s
Explanation:
We can use the third equation of motion to find out the final spinning speed of the wheel:
[tex]2\alpha \theta = \omega_f^2 -\omega_i^2\\[/tex]
where,
α = angular acceleration = 65 rev/s²
θ = No. of revolutions completed = 92 rev
ωf = final angular speed = ?
ωi = initial angular speed = 32 rev/s
Therefore,
[tex](2)(65\ rev/s^2)(92\ rev) = \omega_f^2 - (32\ rev/s)^2\\\omega_f^2 = 11960\ rev^2/s^2 + 1024\ rev^2/s^2\\\omega_f = \sqrt{12984\ rev^2/s^2}[/tex]
ωf = 113.95 rev/s
Now, for the time we can use the first equation of motion:
[tex]\omega_f = \omega_i +\alpha t\\113.95\ rev/s - 32\ rev/s = (65\ rev/s^2)t\\t = \frac{81.95\ rev/s}{65\ rev/s^2}\\\\[/tex]
t = 1.26 s
CORRECT ANSWER GETS BRAINLIEST
Answer:
Wax melts as it absorb heat from flame
Explanation:
To know which option is correct, it is important that we know what chemical changes and physical changes are all about.
Chemical change is a change in which the process is not easily reversed and it produces new substance.
Physical change is more like the opposite of chemical change. In this change, the process is easily reversed and no new substance is produced.
Considering the options given above,
1. Iron combines with oxygen to produce rust is a chemical change since a new substance (rust) is formed and we can not reverse the process to get back iron and oxygen.
2. Wax melts as it absorb heat from flame is a physical change since no new substance is formed and we obtained the wax by allowing it to solidified.
3. Pure sodium explodes when dropped in water is a chemical change because we can not reverse the process to get back the sodium.
4. Glucose molecules are produced in plant leaf is also a chemical change.
From the illustrations above, it is evident that: 'Wax melts as it absorb heat from flame' is not a chemical
HELP HELP HELP HELP HELP PLEASEEE HELP ME WITH MY OTHER QUESTIONS TOO!! PLEASE
does altitude has an effect on weight? HELP
Answer: lose weight at high altitudes.
Explanation:
Answer:
Just a week at high altitudes can cause sustained weight loss, suggesting that a mountain retreat could be a viable strategy for slimming down. Overweight, sedentary people who spent a week at an elevation of 8,700 feet lost weight while eating as much as they wanted and doing no exercise
What my fav food for 20 points if you know it!?
Answer:
pizza
Explanation:
Answer:
sea food???
Explanation:
the density of gold is 19g/m³ what is the volume of 38g
let the volume be x
19 = 38/x
x=38/19
x=2
volume is 2 cm^3
I need help please only way to put my grade up !!!!!! Would appreciate it !!! Someone who’s good at this
Answer:
Total energy = 1000J
KE = 500J
PE = 500J
Explanation:
As you may know, the equation for gravitational potential energy is mgh (weight x height)
If the skateboard is halfway down, that means it is at half the height. As the skateboard speeds up (as it goes downward), the potential energy becomes kinetic energy. Since it has 500J of kinetic energy at half way down, it means it had double that amount of Potential energy at the top (1000J). Since half of that became kinetic energy, there is only 500J of PE left.
Total energy = KE + PE = 1000J
KE = 500J
PE = 500J
what is an axis in social
Answer:
An axis is an invisible line around which an object rotates, or spins. The points where an axis intersects with an object's surface are the object's North and South Poles.
Chemical energy may be released during a chemical reaction in the form of heat ..... True or false?
Answer:
heat and gas sometimes so true
A moving man is lifting a box up an inclined plane. Halfway up he sets the box down and rests. Which of the following explains why the box does not slide back down the inclined plane?
a. The force of friction balances the force of gravity.
b. The force of gravity does not affect inclined planes.
c. The force of friction does not affect inclined planes.
d. The force of friction is less than the force of gravity.
Answer: A or B
Explanation: I’m guessing that they even each other out depending on the incline, gravity will help keeping it in place
You need to load a crate of mass m onto the bed of a truckon earth. One possibility is just to lift the crate straight up over a height h, equal to height of the truck's bed. Theforce exert in this case is F1 and the work done in this case is W1. The other possibility is to slide the crate up the frictionless ramp of length L.. In this case you exert force F2 and perform work W2. Which statement is true?
a. F1 > F2 and W1 > W2
b. F1 = F2 and W1 > W2
c. F1 = F2 and W1 = W2
d. F1 > F2 and W1< W2
e. F1 > F2 and W1 = W2
Answer:
The correct answer is - option E. e. F1 > F2 and W1 = W2
Explanation:
Case 1 - F1 = mg, m= mass and g = gravitational force
Work done W1 = F1h= mgh (h - height of bed of truck)
Case 2 - F2 = mgsinθ
work done W2 = mgsinθ×L (L=length of ramp ans sin θ angle of ramp)
sinθ = h/l, then W2 = mg(h/L)L
W2 = mgh
By comparing both,
F2 = mgsinθ and F1 = mg therefore,
F2>F1
now, W2 = mgh, and W1 = mgh
therefore, W2 = W1.
scholastic science world
CHECK FOR UNDERSTANDING: VIDEO GAME TYCOONS
Which statement is true?
A)
All waves travel at the same speed through any medium.
B)
All waves travel at the same speed if no medium is present.
Electromagnetic waves require a medium, but mechanical waves do not.
D)
Mechanical waves require a medium, but electromagnetic waves do not
Answer:
B.
Explanation:
Which waves can travel through space?
a. Electromagnetic waves only
b. Mechanical waves only
c. Electromagnetic and mechanical waves
d. Longitudinal and electromagnetic waves
Answer:
electromagnetic waves only
Explanation:
I just took the test, Hope it helps!
Answer:
A: Electromagnetic waves only
Explanation:
Neutron stars are extremely dense objects that are formed from the remnants of supernova explosions. Many rotate very rapidly. Suppose the mass of a certain spherical neutron star is twice the mass of the Sun and its radius is 13.0 km. Determine the greatest possible angular speed the neutron star can have so that the matter at its surface on the equator is just held in orbit by the gravitational force. (The mass of the Sun is 1.99 1030 kg.)
Answer:
The required angular speed the neutron star is 10992.32 rad/s
Explanation:
Given the data in the question;
mass of the sun M[tex]_S[/tex] = 1.99 × 10³⁰ kg
Mass of the neutron star
M[tex]_N[/tex] = 2( M[tex]_S[/tex] )
M[tex]_N[/tex] = 2( 1.99 × 10³⁰ kg )
M[tex]_N[/tex] = ( 3.98 × 10³⁰ kg )
Radius of neutron star R[tex]_N[/tex] = 13.0 km = 13 × 10³ m
Now, let mass of a small object on the neutron star be m
angular speed be ω[tex]_N[/tex].
During rotational motion, the gravitational force on the object supplies the necessary centripetal force.
GmM[tex]_N[/tex] = / R[tex]_N[/tex]² = mR[tex]_N[/tex]ω[tex]_N[/tex]²
ω[tex]_N[/tex]² = GM[tex]_N[/tex] = / R[tex]_N[/tex]³
ω[tex]_N[/tex] = √(GM[tex]_N[/tex] = / R[tex]_N[/tex]³)
we know that gravitational G = 6.67 × 10⁻¹¹ Nm²/kg²
we substitute
ω[tex]_N[/tex] = √( ( 6.67 × 10⁻¹¹ )( 3.98 × 10³⁰ ) ) / (13 × 10³ )³)
ω[tex]_N[/tex] = √( 2.65466 × 10²⁰ / 2.197 × 10¹²
ω[tex]_N[/tex] = √ 120831133.3636777
ω[tex]_N[/tex] = 10992.32 rad/s
Therefore, The required angular speed the neutron star is 10992.32 rad/s
A student is investigating the differences between light waves and sound waves. The student does this by using a capsule filled with solid glass at one end and a vacuum at the other end. The student will transmit waves into the capsule at a 30° angle to the (normal) centerline.
alert your teacher if the image is missing
Which >>TWO<< questions should the student ask, and which predictions are MOST LIKELY correct based on this investigation?
Group of answer choices
question: Can electromagnetic waves and mechanical waves travel from a solid glass medium into a liquid medium?
prediction: The electromagnetic waves will continue through the liquid medium, while the mechanical waves will go no farther.
question: How are electromagnetic waves and mechanical waves affected when traveling from a solid glass medium to a vacuum?
prediction: The electromagnetic waves will continue through the vacuum, while the mechanical waves will go no farther.
question: Can electromagnetic waves and mechanical waves travel from a solid glass medium into a liquid medium?
prediction: Both electromagnetic waves and mechanical waves will bend, showing that they have passed through each medium.
question: How are electromagnetic waves and mechanical waves affected when traveling from a solid glass medium to a vacuum?
prediction: The electromagnetic waves and mechanical waves will continue through the vacuum at a lower speed.
question: How is the speed of electromagnetic waves affected when traveling from a solid glass medium to a vacuum at a 30° angle?
prediction: The electromagnetic waves will travel in a straight line, showing that they have maintained a constant speed.
question: How is the speed of electromagnetic waves affected when traveling from a solid glass medium to a vacuum at a 30° angle?
prediction: The electromagnetic waves will bend downward, showing that they have sped up slightly
Answer:
Explanation:
The investigation is on differences between light waves and sound waves. Because the light and sound are transmitted at a 30° angle at a capsule with glass and vacuum, questions asked should show difference answers for light and sound.
First and third question talk about liquid which is not related here.
Fouth and sixth prediction are wrong as electromagnetic wave will not slow down or speed up in vacuum.
That leaves the second and fifth set as correct answers:
question: How are electromagnetic waves and mechanical waves affected when traveling from a solid glass medium to a vacuum?
prediction: The electromagnetic waves will continue through the vacuum, while the mechanical waves will go no farther.
question: How is the speed of electromagnetic waves affected when traveling from a solid glass medium to a vacuum at a 30° angle?
prediction: The electromagnetic waves will travel in a straight line, showing that they have maintained a constant speed.
Answer:
The two questions and predictions are:
question: How are electromagnetic waves and mechanical waves affected when traveling from a solid glass medium to a vacuum?
prediction: The electromagnetic waves will continue through the vacuum, while the mechanical waves will go no farther.
question: How is the speed of electromagnetic waves affected when traveling from a solid glass medium to a vacuum at a 30° angle?
prediction: The electromagnetic waves will travel in a straight line, showing that they have maintained a constant speed.
Explanation:
light is EM wave which is transverse while sound is longitudinal. speed changes for long wave but not EM.
CAN YOU HELP MEEEEEEEEEE PLEASEEEE
Answer:
What are your options? also i believe the answer may be ecosystem.
Explanation:
There are both biotic and abiotic factors in an ecosystem. Be cause living organisms Are Biotic. While water and rocks are abiotic which are needed to form an ecosystem.
A sphere with the same mass and radius as the original cylinder, but a smaller rotational inertia, is released from rest from the top of the ramp. KS and KC are the sphere's and cylinder's total kinetic energy at the bottom of the ramp, respectively. How do KS and KC compare, and why
Answer:
The Kinetic energy of Sphere is higher than the cylinder.
( KS > KC )
Explanation:
Given - A sphere with the same mass and radius as the original cylinder, but a smaller rotational inertia, is released from rest from the top of the ramp. KS and KC are the sphere's and cylinder's total kinetic energy at the bottom of the ramp, respectively.
To find - How do KS and KC compare, and why ?
Proof -
We know that,
The total energy of an object = Potential energy + linear kinetic energy + rotational kinetic energy.
⇒E = mgh + [tex]\frac{1}{2} mv^{2}[/tex] + [tex]\frac{1}{2} l\omega^{2}[/tex]
Now,
Mass of sphere = m
Radius of sphere = r
So,
The moment of inertia of a uniform solid sphere = [tex]\frac{2}{5} mr^{2}[/tex]
Also,
Mass of cylinder = m
Radius of cylinder = r
So,
The moment of inertia of a uniform solid cylinder = [tex]\frac{1}{2} mr^{2}[/tex]
Now,
Total energy for the sphere , Es = mgh + [tex]\frac{7}{10} mv^{2}[/tex]
Total energy for the cylinder, Ec = mgh + [tex]\frac{3}{4} mv^{2}[/tex]
As they always have the same total energy,
So, for height h of the sphere's velocity has to be higher.
Therefore,
The Kinetic energy of Sphere is higher than the cylinder.
Answer:
KS < KC
Explanation:
Brian Lara is a cricketer playing in the field on the second day of a cricket test-match. He exerts a forward force on the 0.145kg cricket ball, as he catches it, to bring it to rest from a speed of 38.2m/s. During the process, his hand recoils a distance of 0.135m. Determine the acceleration of the ball and the force which is applied to it by Brian Lara.
Answer:
a = -3984.6 m/s²
F = 577.76 N
Explanation:
The acceleration of the ball can be calculated by using the third equation of motion:
[tex]2as = v_f^2 - v_i^2\\[/tex]
where,
a = acceleration of ball = ?
s = distance covered = recoil distance = 0.135 m
vf = final speed = 0 m/s
vi = initial speed = 38.2 m/s
Therefore,
[tex]2(0.135\ m)a = (0\ m/s)^2-(38.2\ m/s)^2\\[/tex]
a = -3984.6 m/s²
here negative sign shows deceleration.
Now, for the force applied by Brian Lara will be equal in magnitude but opposite in direction of the force required to stop the ball:
[tex]F = -ma\\F = -(0.145\ kg)(-3984.6\ m/s^2)\\[/tex]
F = 577.76 N
Which diagram best represents the gravitational forces, F, be-
tween a satellite, S, and Earth?
Answer:
Diagram (3).
Explanation:
N3L states that if object A exerts a force on object B, then object B must exert a force of equal magnitude and opposite direction back on object A ([tex]F_{A} = -F_{B}[/tex]).
The diagram which best represents the gravitational forces, F, between a satellite, S, and Earth is; Choice (3).
The Newton's law of gravitation states that the Force of attraction between two objects is directly proportional to the product of their masses and inversely proportional to the square of their distance apart.The law clearly states a Force of attraction; the two objects come towards each other.
Consequently, Choice (3) best represents the gravitational forces, F, between a satellite, S, and Earth.
Read more:
https://brainly.com/question/11460810
Niobium metal becomes a superconductor when cooled below 9K. Itssuperconductivity is destroyed when the surface magnetic fieldexceeds 0.100 T. Determine the maximum current a 2.00-mm-diameterniobium wire can carry and remain superconducting, in the absenceof any external magnetic field.
Answer:
the maximum current is 500 A
Explanation:
Given the data in the question;
the B field magnitude on the surface of the wire is;
B = μ₀i / 2πr
we are to determine the maximum current so we rearrange to find i
B2πr = μ₀i
i = B2πr / μ₀
given that;
diameter d = 2 mm = 0.002 m
radius = 0.002 / 2 = 0.001 m
B = 0.100 T
we know that permeability; μ₀ = 4π × 10⁻⁷ Tm/A
so we substitute
i = (0.100)(2π×0.001 ) / 4π × 10⁻⁷
i = 500 A
Therefore, the maximum current is 500 A
Two vectors are given as A⃗ = 2i^ + 3j^ − 3k^ and B⃗ = -1i^ + 5j^ + 3k^. Find A⃗ ⋅ B⃗
Answer:
A·B = 4
Explanation:
Given that,
Vector A = 2i+3j-3k
Vector B = -i+5j+3k
We need to find the value of A·B.
We know that,
i·i=j·j=k·k = 1 and i·j=j·k=k·i=0
So,
[tex]A\cdot B=(2i+3j-3k)\cdot (-i+5j+3k)\\\\=-2+5(3)+(-3)(3)\\\\=-3+15-9\\\\=4[/tex]
So, the value of A·B is equal to 4.
HELP 30 POINTS
The picture above shows a cross section of the Earth’s interior including both oceanic crust and continental crust. Along the seafloor, there are mid–ocean ridges where magma rises to the surface and creates new crust. There are also areas where crust is recycled as oceanic crust goes below continental crust. What type of boundary would occur at a mid-ocean ridge?
Mid-ocean ridges happen along divergent plate boundaries, where new ocean floor is created as the Earth’s tectonic plates spread apart. As the plates separate, molten rock rises to the seafloor, producing large volcanic eruptions of basalt.
PHYSICS HELP
PLEASE HELP ITS ABOUT ATWOOD MACHINES
Answer:
7.23407 [tex]\frac{m}{s^2}[/tex]
Explanation:
(I will not include units in calculations)
I'm assuming FBD's are already drawn, so I will work from there.
Let the 2.2kg block equal [tex]m_2[/tex], and the 20kg block equal [tex]m_1[/tex].
Summation equation for [tex]m_2[/tex]: [tex]\sum F_x=F_t_2-(F_f+F_g_x)=m_2a[/tex], [tex]\sum F_y=F_n-F_g_y=0[/tex]
Summation equation for [tex]m_1[/tex]: [tex]\sum F_y=F_g-F_t_1=m_1a[/tex]
Torque Summation Equation: [tex]\sum\tau=F_t_1*r-F_t_2*r=I\alpha[/tex]
Do some plugging in with the values given: [tex]\sum\tau=F_t_1*r-F_t_2*r=.5Mr^2\alpha[/tex]
Replace [tex]\alpha[/tex] with [tex]\frac{a}{r}[/tex], and cancel out the r's.
[tex]\sum\tau=F_t_1-F_t_2=.5Ma[/tex]
This step is important: Rearrange the force summation equation to solve for each tension force.
[tex]F_t_2=m_2a+F_f+F_g_x\\F_t_1=m_1g=m_1a[/tex]
Perform Substitution: [tex]\sum\tau=m_1g-m_1a-(m_2a+F_f+F_g_x)=.5Ma[/tex]
Now, we need to find the friction force and the horizontal component of the force of gravity.
Note that [tex]F_f=[/tex]μ[tex]F_n[/tex]
And based on our earlier summation equation: [tex]F_n=F_g_y[/tex]
First, break [tex]F_g[/tex] into x and y components. [tex]F_g_y=F_g\cos(\theta)[/tex], [tex]F_g_x=F_g\sin(\theta)[/tex]
Perform substitution with this and the fact that [tex]F_g=mg[/tex].
[tex]\sum\tau=m_1g-m_1a-(m_2a+\mu*m_2g\cos(\theta)+m_2g\sin(\theta))=.5Ma[/tex]
Solving for a, plugging in numbers yields an answer of 7.23407 [tex]\frac{m}{s^2}[/tex]
Answer:
7.23407
Explanation:
easy
The unit J/Pa is equivalent to
(a) m³
(b) cm³
(c) dm³
(d) None of these
Answer:
(a) m³
Explanation:
Joule is the unit of work and Pascal is unit of pressure.
J/Pa = work/pressure = Nm/Nm⁻² = m³
Thus, The unit J/Pa is equivalent to m³
-TheUnknownScientist
Ilus
A bat bounces a sound wave off a
bird 19.4 m away, and hears the
echo after 0.117 s. What is the
speed of sound in the air?
(Hint: It is not necessarily 343 m/s.)
(Unit = m/s)
Answer:
332m/s
Explanation:
We know the formula for velocity is v=d/t, but this particular question is asking about an echo. The problem tells us the distance to the bird from the bat, which is 19.4. To find the echo, you need to find the distance from the bat to the bird and back.
So
19.4 x 2 = 38.8
And then plug into the equation
v = 38.8 / 0.117
= 332m/s
PLEASE HELP! I'LL GIVE BRAINLEST
Answer:
8.162
Explanation:
W=mg
= 2.2 x 3.71
= 8.162 N
Instead of changing the focal length of the lens, the eyes of amphibians work in a different manner: a set of muscles changes the shape of the eye which increases the distance between the front of the eye and the retina. The world's largest frog, the Goliath frog of west Africa, has an eye with a maximum size similar to a human's: 2.5cm. However, unlike a human, where the focal length is also 2.5cm, the focal length of the Goliath frog's eye is 2.146 cm. What is the maximum distance this frog can see
Answer:
The answer is "15.56 cm".
Explanation:
[tex]v= 2.5 \ cm\\\\f= 2.154 \ cm[/tex]
Calculating object of length is x so:
[tex]u= -x[/tex]
Using formula:
[tex]\to \frac{1}{v}-\frac{1}{u}=\frac{1}{f}\\\\\to \frac{1}{2.5}-\frac{1}{-x}=\frac{1}{2.154}\\\\\to \frac{1}{x}=\frac{1}{2.154}-\frac{1}{2.5}\\\\\to \frac{1}{2.5}-\frac{1}{-x}=\frac{1}{2.154}\\\\\to x= 15.56 \ cm[/tex]
a bag of sugar has a mass of 2.26 kg. what is its weight
Answer:
2260
gimme brainliest rn
A toy car of mass 2.0kg is made to move in a circular track of radius 10.0m. If the centripetal force is 800.0N, calculate the angular velocity of the car
Answer:
w = 6.325 rad/s
Explanation:
Given the following data;
Mass = 2kg
Radius, r = 10m
Centripetal force = 800N
To find the angular velocity of the car;
First of all, we would use the following formula to solve for the speed of the car;
Centripetal force = mv²/r
800 = 2*v²/10
Cross-multiplying, we have;
8000 = 2v²
4000 = v²
Taking the square root of both sides, we have;
v = √4000
v = 63.25 m/s
Next, we find the angular velocity, w using the formula below;
w = v/r
w = 63.25/10
w = 6.325 rad/s