Kinetic Energy Problems 1. A table tennis ball has a mass of about 2.45 g. Suppose the ball is hit across the table with a speed of 4.0 m/s. What is the ball’s kinetic energy?

2. The largest land predator is a male polar bear, which has a mass of around 500.00 kg. If the top speed of a male polar bear is 11.0 m/s, how much KE does it have?

3. What is the KE of a 1.00 kg hammer swinging at 20.0 m/s?

4. Japan’s fasted high speed “bullet” trains, also known as the Shinkansen, travel at a speed of 88.9 m/s. It has an estimated mass of 480,000.0 kg. What is the maximum KE of this train?

Cpowerlifting my boi

Wut 

The figure is missing but we can answer anyway.the correct answer is "releasing the string". in fact, when the person is holding the bow and the arrow, the kinetic energy of the arrow is still zero (because the arrow is not moving). the moment the arrow is released, it acquires a velocity v, so its kinetic energy will become different from zero: where m is the mass of the arrow and v its velocity.  all the other options, instead, do not increase the kinetic energy of the system: -  pulling farther back on the string : this will just increase the elastic potential energy of the system-  holding the arrow higher: this will increase the gravitational potential energy of the system (which is given by u=mgh, where h is the height above the ground)-  decreasing the mass of the arrow: this will decrease the gravitational potential energy of the system (which is given by u=mgh, where m is the mass)

Can you give more detail