Mechanics | Relativity Answers

Sam tosses a ball horizontally off a footbridge at 3.1 m/s. How much time passes after he releases it until its speed doubles?

A juggler throws a ball from height of 0.950 m with a vertical velocity of +4.25 m/s and misses it on the way down. What is its velocity when it hits the ground?

Your friend has climbed a tree to a height of 6.00 m. You throw a ball vertically up to her and it is traveling at 5.00 m/s when it reaches her. What was the speed of the ball when it left your hand if you released it at a height of 1.10 m?

A 1250kg car is pulling a 325kg trailer. Together, the car and the trailer have an acceleration of 2.15 m/sec[sup]2[/sup].
Determine the net force on the car-trailer combination.
What is the net force on the trailer?

An electron starts at rest. Gravity accelerates the electron in the negative y direction at 9.80 m/s2 while an electric field accelerates it in the positive x direction at 3.80×106 m/s2. Find its velocity 2.45 s after it starts to move.

A cannon mounted on a pirate ship fires a cannonball at 125 m/s horizontally, at a height of 17.5 m above the ocean surface. Ignore air resistance. (a) How much time elapses until it splashes into the water? (b) How far from the ship does it land?

A box is dropped from a spacecraft moving horizontally at 27.0 m/s at a distance of 155 m above the surface of a moon. The rate of freefall acceleration on this airless moon is 2.79 m/s2. (a) How long does it take for the box to reach the moon's surface? (b) What is its horizontal displacement during this time? (c) What is its vertical velocity when it strikes the surface? (d) At what speed does the box strike the moon?

A friend throws a baseball horizontally. He releases it at a height of 2.0 m and it lands 21 m from his front foot, which is directly below the point at which he released the baseball. (a) How long was it in the air? (b) How fast did he throw

A long jumper travels 8.95 meters during a jump. He moves at 10.8 m/s when starts his leap. At what angle from the horizontal must he have been moving when he started his jump? You may need the double-angle formula: 2 sin u cos u = sin (2u)

What is the Difference between Mass and Weight?