a boy whose weight is 600N runs up a fight of stairs 10m high in 12s. what is his average power​

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

Answer:

electromagnetic waves only

Explanation:

I just took the test, Hope it helps!

Answer:

A: Electromagnetic waves only

Explanation:

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.

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 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.

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Answer:

heat and gas sometimes so true

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.

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

Answer:

pizza

Explanation:

Answer:

sea food???

Explanation:

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.

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]

Answer:

1st and 2nd

Explanation:

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.

Answer:

1

Explanation:

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.

Answer:

8.162

Explanation:

W=mg

  = 2.2 x 3.71

  = 8.162 N

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

Answer:

2260

gimme brainliest rn

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

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

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

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

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

Explanation:

3

i believe that they are all going at 3.2 meters each, I did 4 times 0.8

The velocity of each electron at the corners of the square is 15.92 m/s.

The given parameters;

The diagonal length of the square is calculated as;

[tex]d^2 = 0.8^2 + 0.8^2\\\\d = \sqrt{0.8^2 + 0.8^2} \\\\d = 1.13 \ m[/tex]

The distance of each corner charge and the middle charge is calculated as;

[tex]r = \frac{1.13}{2} \\\\r = 0.565 \ m[/tex]

The force between each corner charge and the middle charge is calculated as;

[tex]F= \frac{kq^2}{r^2}[/tex]

The centripetal force on each charge moving around the square is calculated as;

[tex]F = \frac{mv^2}{r}[/tex]

solve the forces together;

[tex]\frac{mv^2}{r} = \frac{kq^2}{r} \\\\v^2 = \frac{kq^2}{m} \\\\v = \sqrt{ \frac{kq^2}{m} } \\\\v = \sqrt{ \frac{(9\times 10^9) \times (1.602\times 10^{-19})^2}{9.11 \times 10^{-31}} } \\\\v = 15.92 \ m/s[/tex]

Thus, the velocity of each electron at the corners of the square is 15.92 m/s.

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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

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.

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:

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