Answer:
2 ms^2
Explanation:
Given that the mass of the refrigerator is 200Kg
The net force acting on the refrigerator is 400N
The time takes is 4s
From Newtons's second law of motion;
F =ma
a = F/m
a = 400/200
a = 2 ms^2
This is a constant acceleration
Answer:

Explanation:
The minimum total work is the work needed to counteract the work associated with the weight:




Answer:
the answer is Natural selection
Explanation:
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Answer:
The ball stops instantaneously at the topmost point of the motion.
Explanation:
Assume we have thrown a ball up in the air. For that we have given a force on the ball and it acquires an initial velocity in the upward direction.
The forces that resist the motion of the ball in the upward direction are the force of gravity and air resistance. The ball will instantaneously come to rest when the velocity of the ball reduces to zero.
The two forces acting in the downward direction reduces its speed continuously and it becomes zero at the topmost point.