Answer:
true
Explanation:
Friction occurs because no surface is perfectly smooth. Rougher surfaces have more friction between them. Heavier objects also have more friction because they press together with greater force. Friction produces heat because it causes the molecules on rubbing surfaces to move faster and have more energy.
Answer:
The thrust is 
Explanation:
Given that,
Mass of gas, 
The rate at which the gas is expelling, 
We need to find the thrust produced by the gas.
We know that force is equal to the rate of change of momentum. So,

Also, p = mv

So,

So, the thrust is 
If the object's kinetic energy is zero, then due to in multiplication factor, it's momentum will also be equal to zero 'cause the velocity of the object must be Nil
In short, Your Answer would be: "Zero"
Hope this helps!
The average power produced by the soccer player is 710 Watts.
Given the data in the question;
- Mass of the soccer player;

- Energy used by the soccer player;

- Time;

Power; 
Power is simply the amount of energy converted or transferred per unit time. It is expressed as:

We substitute our given values into the equation
![Power = \frac{5100000J}{7200s}\\\\Power = 708.33J/s \\\\Power = 710J/s \ \ \ \ \ [ 2\ Significant\ Figures]\\\\Power = 710W](https://tex.z-dn.net/?f=Power%20%3D%20%5Cfrac%7B5100000J%7D%7B7200s%7D%5C%5C%5C%5CPower%20%3D%20708.33J%2Fs%20%5C%5C%5C%5CPower%20%3D%20710J%2Fs%20%5C%20%5C%20%5C%20%5C%20%5C%20%5B%202%5C%20Significant%5C%20Figures%5D%5C%5C%5C%5CPower%20%3D%20710W)
Therefore, the average power produced by the soccer player is 710 Watts.
Learn more: brainly.com/question/20953664