In the mirror diagram, which is the normal

Aman tries to push a box of mass 4 kg with a force of 5 n but the box remains stationary if the coefficient of static friction is 0.45, what is the value of the maximum force of friction?

Auniform crate c with mass mc is being transported to the left by a forklift with a constant speed v1. what is the magnitude of the angular momentum of the crate about point a, that is, the point of contact between the front tire of the forklift and the ground

An alien spaceship is 500 m above the ground and moving at a constant velocity of 150 m/s upwards. how high above the ground is the ship after 5 seconds?