Winston stands on the edge of a building's flat roof, 12 m above the ground, and throws a 147.0-g baseball straight down. the ball hits the ground at a speed of 18 m/s. what was the initial speed of the ball?

A person rubs her hands together and they heat up • kinetic energy • light energy • sound energy • electrical energy • chemical energy • heat energy (multiple choice)

Devon has several toy car bodies and motors. The motors have the same mass, but they provide different amounts of force, as shown in this table Which motor and body should Devon use to build the car with the greatest acceleration?

Find the displacement current through a parallel-plate capacitor. Assume that V is the voltage across the capacitor at any instant. Express your answer in terms of the variables C and dV/dt.

What are some things cyclists do to reduce friction?

It takes 105 j of work to move 2.7 c of charge from the negative plate to the positive plate of a parallel plate capacitor. what voltage difference exists between the plates?

What kind of star gives rise to a type i supernova? a. white dwarf stars b. massive main sequence stars c. red giant stars?

Example of an object in motion

A proton and an alpha particle are momentarily at rest at a distance r from each other. They then begin to move apart. Find the speed of the proton by the time the distance between the proton and the alpha particle doubles.

Why is it a good idea to extend your bare hand forward when you are getting ready to catch a fast-moving baseball? a. So you can catch the ball with a stiff arm, increasing the time to slow the ball thus deceasing the force. b.

At room temperature what is the strength of the electric field in a 12-gauge copper wire (diameter 2.05 mm that is needed to cause a 2.75 a current to flow?