How much work is done when lifting a barbell with two plates that has mass of 45 kg from the ground to 1.5 meters about ground level? What is the power if it takes 3 seconds to complete this task?

For general projectile motion, when the projectile is at the highest point of its trajectory, its acceleration is zero? a)the horizontal and vertical components of its velocity are zero. b) its velocity is perpendicular to the acceleration. c)the horizontal component of its velocity is zero. d)its velocity and acceleration are both zero.

If forces acting on an object are unbalanced. true or false

Give an example of a collision in real life. use the law of conservation of energy to describe the transfer of momentum. be sure and discuss the momentum before and after the collision occurs. you will need at least 3 sentences to thoroughly answer this question.