21. A ball is dropped straight down to the ground from the top of a building. The wind blows from the east, pressing on the ball with a force of 5 newtons. How does the wind most likely affect the motion of the ball?
A. The wind is an unbalanced force and will cause the ball to change directions.
B. The wind is a balanced force and will not make any changes to the motion of the ball.
c. The wind is a balanced force and will cause the ball to change directions.
D. The wind is an unbalanced force and will not make any changes to the motion of the ball.

Which are advantages of renewable resources? check all that apply. renewable energy supplies are completely reliable everywhere. some renewable resources will never be used up. little or no waste is produced by renewable resource plants. electricity can be generated in large quantities. many renewable energy facilities have lower operating costs.

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arranged side by side so that they are parallel to each other. when you push the platform, you compress the springs. you do an amount of work of 79.0 j when you compress the springs a distance of 0.230 m from their uncompressed length. (a) what magnitude of force must you apply to hold the platform in this position? (b)how much additional work must you do to move the platform a distance 0.230 m farther? (c) what maximum force must you apply to move the platform a distance 0.230 m farther?