Answer:
F = 47.6 N
Explanation:
- Newton's 2nd law can be expressed as the rate of change of the total momentum, respect of time, as follows:

- So, in order to find the average force exerted by the skater on the wall, we can find the change in momentum due to the force exerted by the wall (which is equal and opposite to the one exerted by the skater), and divide it by the time interval , as follows:

⇒ Fsk = 47.6 N (normal to the wall)
The thermal efficiency of an engine is

where
W is the work done by the engine
Q is the heat absorbed by the engine to do the work
In this problem, the work done by the engine is W=200 J, while the heat exhausted is Q=600 J, so the efficiency of the machine is
Answer:
Energy cannot be created or destroyed.
Explanation:
its in the name, law of "conservation" of energy. energy can only change forms not be destroyed
I would say radio waves infared rays and xray
Answer:
yes
Explanation:
because there going the same speed but in different directions.