Jerome solves a problem using the law of conservation of momentum. What should Jerome always keep constant for each object after the objects collide and bounce apart?
a-velocity
b-mass
c-momentum
d-direction
Answer:
b. Mass
Explanation:
This question has to do with the principle of the law of conservation of momentum which states that the momentum of a system remains constant if no external force is acting on it.
As the question states, two objects collide with each other and eventually bounce apart, so their momentum may not be conserved but the mass of the objects is constant for each non-relativistic motion. Because of this, the mass of each object prior to the collision would be the same as the mass after the collision.
Therefore, the correct answer is B. Mass.
Answer:
750W
Explanation:
40×10= 400N
work done= force × distance
=400 × 75
=30000 J
Power= work done/ time
= 30000 ÷ 40
= 750 W
We can solve the problem by using the first law of thermodynamics:

where
is the change in internal energy of the system
is the heat absorbed by the system
is the work done by the system on the surrounding
In this problem, the work done by the system is

with a negative sign because the work is done by the surrounding on the system, while the heat absorbed is

with a negative sign as well because it is released by the system.
Therefore, by using the initial equation, we find
