Motivate me for my exam
1 answer:
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Answer:
Explanation:
Given:
- mass of the object on a horizontal surface,
- coefficient of static friction,
- coefficient of kinetic friction,
- horizontal force on the object,
<u>Now the value of limiting frictional force offered by the contact surface tending to have a relative motion under the effect of force:</u>
where:
normal force of reaction acting on the body= weight of the body
As we know that the frictional force acting on the body is always in the opposite direction:
So, the frictional force will not be at its maximum and will be equal in magnitude to the applied external force and hence the body will not move.
so, the frictional force will be:
Hello!
<em>a) What is the change in momentum</em>?
The change of the momentum is the velocity, because the velocity is reduced to zero.
We can calculate the aceleration, applicating the formula:
Like you see, the final velocity will be zero, so:
Like you see, the aceleration applicate by superman is of <u>-10 m/s^2.</u>
If the aceleration is negattive, means the velocity will decrease.
<em>b.) What is the magnitud of the force wich superman exerts on the train?</em>
For calculate the force applicate for superman, lets applicate the second law of Newton:
Lets replace and resolve it:
F = 8x10^3 kg * (-10 m/s^2)
F = 8000 kg * (-10 m/s^2)
F = -80 000 N
The force applicated is of <u>-80000 Newtons.</u>
When the force is negative means the force applicated in the another direction of the object what is traveling.
A free-falling object is an object moving under the effect of gravitational forces alone
The correct option to select for the True or False question is False
The reason the above selected option is correct is as follows:
According to Newton's second law of motion, we have;
Force = Mass × Acceleration
The force of gravity is
Where;
m = The mass of the object
∴ The force acting on an object in free fall, = m × g
Therefore the acceleration of an object in free fall is the constant acceleration due to gravity, and it therefore, does not change with time
The correct option for the question, acceleration of a free-falling object in a frictionless environment increases as a function of time is <u>False</u>
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Learn more about object in free fall here: