Question1
A dock worker loading crates on a ship ?nds that a 24 kg crate, initially at rest on a horizontal surface, requires a 63 N horizontal force to set it in motion. Though, after the crate is in motion, a horizontal force of 47 N is necessary to keep it moving with a constant speed.
The acceleration of gravity is 9.8 m/s
Find out the coefficient of static friction between crate and floor.
Question2
When a piece of wood is pressed against a spring and compresses the spring by 4.00{rm cm}, wood gains a utmost kinetic energy K when it is released.
How much kinetic energy (in terms of K) would the piece of wood gain if the spring were compacted 15.8 {rm cm} instead?
Question3
A 135 g baseball, moving along x-axis with speed 33.0 m/s, strikes a fence at a 45 degree angle and rebounds along the y-axis with unchanged speed. Provide the x and y components of its change in momentum.