Answer:
b. Medicine balls
Explanation:
A medicine ball (also called an exercise ball, or a health ball) is a weighted ball about the shoulder diameter (approx. 13.7 inches), often used for recovery and strength training.... In 1705 similar large balls had been used in Persia.So you can use your medicine ball as a projectile to boost the strength of your throws.
Answer: Yes
Air serves as a propagation medium.
Explanation:
Propagation of sound wave require a medium for transmission. Sound is produced by vibrating objects, The matter or substance through which sound is transmitted is called a medium. It can be solid, liquid or gas. Therefore to propagate sounds (human voice) from one end of a lecture hall to the other we need a propagation medium which is air. Air serves as a propagation medium.
You should have the velocity as a function of time either given explicitly or implicitly (a graph)
v = ds/dt (differentiating the position vector)
integrating the acceleration.
you can use impulse or work and energy principle and also newton law of motion to find acceleration then velocity
NOT SURE IF THAT WHAT YOU WANT.