In the image below, a worker is pushing a crate with a mass of 25 kg up a ramp at a constant rate. Ignoring friction, how much force must the worker apply so that the crate continues to move at the same speed? (Recall that g = 9.8 m/s2)

A. 35.3N
B. 83.8N
C. 50.2N
D. 16.2N

Write short note on the following ; collision theory, rotation angle and angular velocity, centripetal acceleration, coriolis force, and newton's law of gravitation.

Apulley system is used to lift a 2,000 newton engine up a distance of 3 meters. the operator must apply a force of 250 newtons to the chain of the pulley system to lift the motor. to lift the engine 3 meters, the operator must pull a total of 30 meters of chain through the pulley system. what is the value of di?

Convection currents are caused by differences in what two things?