How is a magnetic field generated?

a. gravity

b. moving electric charges

c. charged particles that do not move

d. an isolated magnetic pole?

Types of energy transferred from mechanical waves

Calculate the earth's gravity force on a 65 kg astronaut who is repairing the hubble space telescope 600 km above the earth's surface

A 4.3 kg bowling ball is initially at rest. If a 15 N force acts on it for 0.85 s, what is the final velocity of the bowling ball?

According to Newton's 3rd Law, an object's momentum depends on it's velocity and mass. 4 dog-sled teams competed to see who could gain the greatest momentum.

if a balloon filled with helium weighs 21.6 kg, knowing that helium's density is 0.18 kg/m3 then what is its volume?

A geologist estimates that a large boulder weighs 7840 N. What should he estimate the mass of this boulder to be? A. 650 kg B. 740 kg C. 780 kg D. 800 kg

Two objects have the same momentum. Do the velocities of these objects necessarily have (a) the same directions and (b) the same magnitudes? Give your reasoning in each case.

If you keep voltage constant and increase resistance resistance, what happens to current?

A scene in a movie has a stuntman falling through a floor onto a bed in the room below. The plan is to have the actor fall on his back, but a researcher has been hired to investigate the safety of this stunt.

During energy transformation, all energy systems: are a. 100 percent efficient b. lose energy c. gain heat energy d. create energy