Answer:
A: 15 m/s
Explanation:
If air resistance was not there, then the ball would not stop moving unless your friend, gravity, and the ground catches it.
Answer:
Work input = 1620
Explanation:
Given the following data;
Work output = 810
Efficiency = 50%
To find the work input;
Mathematically, efficiency is given by the formula;
Substituting into the formula, we have;
Cross-multiplying, we have;
Work input = 1620
Amplitude of a sound wave
Answer:
D) The ball exerts a force on the wall and the wall exerts a force back.
Explanation:
Newton's third law of motion states that:
"When an object A exerts a force on another object B, then object B exerts an equal and opposite force on object A"
In this problem, we can identify (for instance) object A with tha ball and object B with the wall. Therefore, if we apply Newton's third law, we get:
The ball (object A) exerts a force on the wall (object B), therefore the wall (object B) exerts an equal and opposite force on the ball (object A). So, option D is the correct one.