Answer:
[tex]\mathrm{(a)\:}32,000,000\:\mathrm{Ns},\\\mathrm{(b)\:}390,000\:\mathrm{N}[/tex]
Explanation:
The impulse-momentum theorem states the impulse on an object is equal to the change in momentum of that object. Momentum is given by [tex]p=mv[/tex]. Since mass is constant, the train's change in momentum is:
[tex]\Delta p=m\Delta v=750,000\cdot42=31,500,000=\fbox{$32,000,000\:\mathrm{Ns}$}[/tex](two significant figures).
Impulse is also given as [tex]\Delta p = F\Delta t[/tex], where [tex]F[/tex] is the average force applied and [tex]\Delta t[/tex] is change in time. Since [tex]t[/tex] is given as [tex]80\mathrm{s}[/tex], we have the following equation:
[tex]F\Delta t=\Delta p\\\\F=\frac{\Delta p}{\Delta t},\\\\F=\frac{31,500,000}{80},\\\\F=393,750=\fbox{$390,000\:\mathrm{N}$}[/tex](two significant figures).
Which of the following quantities are vectors?
charges
electric fields
energy
potentials
Answer:
electric fields
Explanation:
asap plz help me
Which option identifies the importance of Snow’s scientific work to the medical community?
It was the foundation for epidemiology.
It pioneered the invention of vaccines.
It was the foundation for germ theory.
It created sterilization techniques.
Prior to germ theory, how were diseases thought to be transmitted?
human contact
animal contact
poisonous air
spoiled food
Answer:
It founded the foundation for epidemiology Human contactThe answer are:
1. It founded the foundation for epidemiology.2. poisonous airWhat is the speed of a person travelling 30 meters in 5 seconds?
Answer:
[tex]6\:\mathrm{m/s}[/tex]
Explanation:
Denote average speed by [tex]S=\frac{d}{t}[/tex] where [tex]d[/tex] is total distance travelled and [tex]t[/tex] is time.
Plugging in given values, we get:
[tex]S=\frac{30}{5}=\fbox{$6\:\mathrm{m/s}$}[/tex].
Answer:
s
Explanation:
Select the correct answer.
A stone is dropped from a tower 100 meters above the ground. The stone falls past ground level and into a well. It hits the water at the bottom
of the well 5.00 seconds after being dropped from the tower. Calculate the depth of the well. Glven: g=-9.81 meters/second?
A.22.5 meters
B.50.7 meters
C.100 meters
D.110 meters
E.152.45 meters
Answer:
A
Explanation:
Givens
d = 100 meters plus the depth of the well
d = 100 + x where x is the depth of the well.
vi = 0 m/s The object is dropped. It was not thrown.
t = 5 seconds
a = 9.81 m/s^2
formula
d = vi*t + 1/2 a t^2
solution
100 + x = 0 + 1/2 * 9.81 * 5^2
100 + x = 122.625 Subtract 100 from both sides
x = 122.625 - 100
x = 22.6 m
The well is 22.6 meters deep.
What nuclear reaction is shown in the equation below?
A. Nuclear fusion
B. Nuclear fission
C. Positron emission
D. Beta decay
The carbon isotope was cobined with the proton to produce the nitrogen isotope hence it is a fusion reaction.
What is a nuclear fusion?The term nuclear fusion refers to a kind of reaction in which two nuclei fuse together to give rise to a single nuclei with the evolution of energy.
We can see that the carbon isotope was cobined with the proton to produce the nitrogen isotope hence it is a fusion reaction.
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Answer:
A. Nuclear fusion
Explanation:
got it right, trust
This is very hard, I don't understand.
Answer:
[tex]4x - 6 = 90 \\ 4x = 96 \\ \boxed{x = 24}[/tex]
Now, AD is an altitude of∆ABC
Therefore, D is the midpoint of BC
[tex]x + 7 = 2x - 15 \\ \boxed{x = 22}[/tex]
CD is (22+7) = 29 & DB is (2×22-15) = 29
[tex] \huge \boxed{\: x = 24 }\\ \huge \boxed{CD \: and \:DB= 29}[/tex]
Two billiard balls of equal mass collide. Ball 1 is initially moving at 0.43 m/s to the left, and ball 2 is initially at rest. Which of the following sets of final velocities does not describe an inelastic collision between the balls?
A. Ball 1 at 0.12 m/s left, Ball 2 at 0.31 m/s left
B. Ball 1 at 0.21 m/s left, Ball 2 at 0.22 m/s left
C. Ball 1 at 0.10 m/s left, ball 2 at 0.33 m/s left
D. Ball 1 at rest, ball 2 at 0.43 m/s left
Answer: B
"Ball 1 at 0.21 m/s left, Ball 2 at 0.22 m/s left"
IS IT B!! if not pls helpp!
Answer:
I believe you are correct but we just started this unit
Explanation:
Find the density of a solid object whose mass is 315g, given that its length is 7cm,
width is 3cm and height is 5cm. b) State the unit for measuring density.
Thanks for helping
Answer:
Density is the mass of an object divided by its volume. ... Density often has units of grams per cubic centimeter ... Density is not something that is directly measured.
Explanation:
given
mass (m) = 315 g
length (l) = 7 cm
width (b) = 3 cm
height (h) = 5 cm
Now
volume (v) = l * b * h
V = 7 * 3 * 5
V = 105 cm³
Density (d) = ?
We know
density is defined as mass per unit volume so
d = m / v
d = 315 / 105
d = 3 g/cm³
Therefore density = 3 g/cm³
Note
If the question is asked to write in SI unit of density then u have to write the unit of density as kg/m³
Hope it will help :)
Bob the Builder is making a delivery of wood in his work truck. He is traveling at the velocity of 12 mi/hour at the top of the hill. Nine seconds later he reaches the bottom of the hill and is moving north at 25 mi/hour. What is the acceleration?
Answer:
Acceleration, a = 0.65m/s² due North.
Explanation:
Given the following data;
Initial velocity = 12mi/hr
Final velocity = 25mi/hr
Time = 9 secs
To find the acceleration;
First of all, we would convert miles per hour to meters per seconds.
[tex] Initial \; velocity = \frac {12 * 1609.344}{60*60} = \frac {19312.128}{3600} = 5.37m/s [/tex]
[tex] Final \; velocity = \frac {25 * 1609.344}{60*60} = \frac {40233.6}{3600} = 11.18m/s [/tex]
Now to find the acceleration;
Mathematically, acceleration is given by the equation;
[tex]Acceleration (a) = \frac{final \; velocity - initial \; velocity}{time}[/tex]
Substituting into the equation, we have;
[tex]a = \frac{11.18 - 5.37}{9}[/tex]
[tex]a = \frac{5.81}{9}[/tex]
Acceleration, a = 0.65m/s² due North.
(a) Explain the advantage of using a plane mirror in optical testing.
explain your answer
Answer: Optical test is a test which is used to assess vision and ability of the person to focus on the objects.
Explanation:
The following are the advantages of utilizing plane mirror in optical testing:
1. When a plane mirror is used for testing the image of the test card must be placed at distance equal to the distance of the object.
2. Larger distance in between the object or test card and viewer is obtained. This can help in determining the exact ability of the eye to focus on objects.
Sound is repeated near hills.why
Answer:
Sound waves are reflected back
If the mass of an object increases, then its kinetic energy will ____________ because __________________________
Answer:
when mass will increase then kinetic energy will also increase because both have positive relationship
Explanation:
when volume increase then molecule come closer then more movement will occurs and kinetic energy increase
how is velocity ratio of wheel and axle calculatedaad
Answer:
VR = [tex]\frac{Radius of wheel}{Radius of axle}[/tex]
Explanation:
A machine is a device that can be used to overcome a load by the application of an effort through a pivot. Examples are: pulleys, wedge, screw jack, wheel and axle etc.
The wheel and axle is a simple device that can be used to lift a load through a height. Its velocity ratio (VR) can be determined by:
VR = [tex]\frac{Radius of wheel}{Radius of axle}[/tex]
Note that for a practical wheel and axle, the radius of the wheel is greater than the radius of the axle.
A 10.0kg box sits at rest on ramp that has an incline of 20.0° from the horizontal. What is the force of gravity acting on the box?
A. -98.0N
B. 98.0N
C. -92.1N
D. -33.5N
Answer:
98.0N
Explanation:
A 1.0-kilogram rubber ball traveling east at 4.0 meters per second hits a wall and bounces back toward the west at 2.0 meters per second. Compared to the kinetic energy of the ball before it hits the wall, the kinetic energy of the ball after it bounces off the wall is
Answer:
8 J and 2 J
Explanation:
Given that,
Mass of the rubber ball, m = 1 kg
Initial speed of the rubber ball, u = 4 m/s (in east)
Final speed of the rubber ball, v = -2 m/s (in west)
We need to find the kinetic energy of the ball before it hits the wall, the kinetic energy of the ball after it bounces off the wall.
Initial kinetic energy,
[tex]K_i=\dfrac{1}{2}mv^2\\\\K_i=\dfrac{1}{2}\times 1\times (4)^2\\\\K_i=8\ J[/tex]
Final kinetic energy,
[tex]K_f=\dfrac{1}{2}mv^2\\\\K_f=\dfrac{1}{2}\times 1\times (2)^2\\\\K_f=2\ J[/tex]
So, the initial kinetic energy is 8 J and the final kinetic energy is 2 J.
The kinetic energy of the ball after it bounces off the wall is 2.0 Joules.
The kinetic energy of an object is the energy that is in motion or performing work. It can be expressed by using the formula:
[tex]\mathbf{K.E = \dfrac{1}{2}mv^2}[/tex]
The mass of the object(rubber ball) = 1.0 kgThe initial speed of the rubber ball before the collision = 4.0 m/sThe final speed of the rubber ball after the collision = - 2.0 m/sThe Kinetic energy of the ball after the collision and when it bounces off the wall is computed as:
[tex]\mathbf{K.E = \dfrac{1}{2} \times 1 \times 2.0^2}[/tex]
K.E = 2.0 Joules
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find the cp of an article which is sold for rupees 4048 , thereby , making a profit of 15 percent
Answer:
4048 = 115x/100.
Explanation:
Profit P = (15/100) X x.
P= 15x/100.
15x/100 = 4048- x.
4048 = 15x/100 + x.
4048 = 115x/100.
Intensitatea curentului electric a unui circuit este de 123A iar sarcina electrica este de 1,7C sa se afle intervalul de timp in care este transportata sarcina electrica
The intensity of the electric current of a circuit is 123A and the electric charge is 1.7C to find the time interval in which the electric charge is transported.
Given that,
Current, I = 123 A
Electric charge, q = 1.7 C
To find,
The time interval in which the charge is transported.
Solution,
The electric current is given by electric charge per unit time. So,
[tex]I=\dfrac{q}{t}\\\\t=\dfrac{q}{I}\\\\t=\dfrac{1.7}{123}\\\\t=0.0138\ s[/tex]
So, the required time is 0.0138 seconds.
What 2 factors impact gravitational pull?
mass and distance
matter and energy
size and shape
speed and direction
Answer:
When dealing with the force of gravity between two objects, there are only two things that are important – mass, and distance. The force of gravity depends directly upon the masses of the two objects, and inversely on the square of the distance between them
Can someone please help? Please?
Answer:
I think A= 5M/S is answer
If Minnie the Mouse starts moving at 2m/s and increases her velocity to 4m/s because she is being chased, what is heracceleration if the time is 2 seconds?
Answer:
1m/s²
Explanation:
Given parameters:
Initial velocity = 2m/s
Final velocity = 4m/s
Time of chase = 2s
Unknown:
Acceleration = ?
Solution:
Acceleration is the rate of change of velocity with time;
A = [tex]\frac{v - u }{t}[/tex]
A is the acceleration
v is the final velocity
u is the initial velocity
t is the time taken
A = [tex]\frac{4 - 2}{2}[/tex] = 1m/s²
PLEASE HELP ASAP!!!!!
Carrie pulls a 41.5 kg bin across the floor of her garage using a rope that is attached to the bin. She pulls with a force of 138 N, at an angle of 28.0° above horizontal. The coefficient of kinetic friction between the floor and the box is 0.290 . What is the acceleration of the box?
Answer: 0.81N
Explanation: Fwx = .165x 9.81 Silicon 30 = 0.81N
a train has an initial velocity of 44m/s and an accelaration of _4m/s calculate its velocity
Answer:
It's 4m/s
Explanation:
V = u _ at, at u = 44m/s
44 + [-4]10
4m/s
How does a wheel and axle make work easier?
The wheel and axle is a simple machine that reduces the friction involved in moving an object, making the object easier to transport. ... Once the object is moving, the force of friction opposes the force exerted on the object. The wheel and axle makes this easier by reducing the friction involved in moving an object.
In addition to reducing friction, a wheel and axle can also serve as a force multiplier, according to Science Quest from Wiley. If a wheel is attached to an axle, and a force is used to turn the wheel, the rotational force, or torque, on the axle is much greater than the force applied to the rim of the wheel.
In the diagram shown above, the circles represent small balls that have
electric charges. Ball 1 has a negative charge, and ball 2 is repelled by ball 1
Next, you see that ball 2 repels ball 3 and that ball 3 attracts ball 4. What is
the electric charge on ball 4?
Ball 4 may have either a positive or negative charge,
Ball 4 has a negative charge.
Ball 4 has a positive charge.
Answer:
ball 4 has a positve charge
Explanation:
-Ball 2: is negative because it is repelled by ball one (like signs repel)
- ball 3: is also negative because it is repelled by ball one (like signs repel)
- Ball 4: is positive because it is attracted by ball 3 (opposite signes attract)
When a cyclist is decelerating uphill the forces on him are balanced or unbalanced
Answer:
Unbalanced
Explanation:
A cyclist decelerating uphill has unbalanced forces acting on him. An unbalanced force acting on a body has a net force which is greater than zero. When a body is accelerating or decelerating, the forces are not balanced.
A body with a net force of zero has balanced forces acting on it. Such body is moving with constant acceleration. According to newton's first law of motion" a body will remain in state of rest or of uniform motion unless an external force acts on it". The external force causes acceleration to change drastically.Help !!!!!!!!
Please its Urgent.
None can.
A clinical thermometer only measures temperatures above +30°C.
Mercury and alcohol are both frozen solid at -50°C.
Write a message to Mr. Chang explaining why the groundwater heating system will warm the school more than the water heater system. Use evidence to support your claim. For each piece of evidence you use, explain how the evidence supports your claim.
Answer:
For, heating purposes more the quantity of water more will be the heating. Clearly, underground heating would have more water and hence, it will have edge over the water heater system.
Moreover, for things at the same temperature, the thing with more molecules has more total kinetic energy (thermal energy) than the thing with fewer molecules. The groundwater heating system uses heat from the heat stored naturally in groundwater or aquifers. Thus, saving the cost of power required to heat in normal water heater.
Explanation:
The groundwater heating system will warm the school more than the water heater system due to the fact that it uses more water more than the other system.
Based on the complete question, it should be noted that the addition of energy leads to an increase in motion which results in the rise in temperature.
The groundwater heating system will warm the school more than the water heater system due to the fact that it uses more water more than the other system even though its water isn't as warm as in the other system.
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What does ionic bond mean
Answer:
The acception and donation of elections within two elements is called as ionic bond.MARK ME AS A BRAINLIST AND FOLLOW ME :)Who is the father of Nuclear Physics?
Answer:
Ernest Rutherford, 1st Baron Rutherford of Nelson