What is the difference between a group and a period

What is the best way to show forces

When a soccer ball is headed from one player #1 to player #2 across the soccer field, what is the projectile? A. player #2 B. soccer field C. player #1 D. Soccer field

At which angle must a laser beam enter the water for no refraction to occur?

The energy provided each hour by heat to the turbine in an electric power plant is 9.0*10^12 J. If 5.4 * 10^12 J of energy is exhausted each hour from the engine as heat, what is the efficiency of this heat engine?

A beam contains 2.0 $ 108 doubly charged positive ions per cubic centimeter, all of which are moving north with a speed of 1.0 $ 105 m/s.

How can we calculate the density of a sustance that has irregular volume

A two stage rocket leaves its launch pad moving vertically with an average acceleration of 4 m/s2. at 10 s after launch the first stage of the rocket (now without fuel) is released.

A liquid filled sealed system has cylinders with movable pistons on each end. The face of one piston has an area of 5 cm². The other piston has an area of 500 cm² and is supporting a weight of 2 kN on it.

A turntable is spinning on a frictionless axle when a ball of putty is dropped onto it from above. The putty sticks to the turntable when it lands. Is angular momentum conserved for the turntable and putty (the system) during this process?

A cheetah can run from 0 to 70 mph in 2.2 seconds. what is the cheetah's top speed in m/s?