Answer:
Explanation:
1. False
The force you apply on crate is equal and opposite to the force that crate applies on you by Newton's third law of motion.
The force must over come the static frictional force between the crate and the floor.
2. True
The object can move along another direction than the direction of net force. For example, when a car slows down, the net force is opposite to the direction of motion.
3. True
An object moving at constant velocity has zero net force acting on it.
4. False
An object at rest has forces acting on it but the summation of all the forces is zero i.e. the net force is zero.
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Answer:
0.906
Explanation:
Let g = 9.81 m/s2. We can calculate the rate of change in potential energy when m = 201kg of water is falling down a distance of h = 131m per second

So the efficiency of the water turbine is the ratio of output power over input power:

Answer:
The direct answer to the question as written is as follows: nothing happens to gravity when someone jumps up - gravity continues exerting a force on the body of that particular someone proportional to (mass of someone) x (mass of Earth) / (distance squared). What you might be asking, however, is what is the net force acting on the body of someone jumping up. At the moment of someone jumping up there is an upward acceleration, i.e., an upward-directed force which counteracts the gravitational force - this is the net force ( a result of the jump force minus gravity). From that moment on, only gravity acts on the body. The someone moves upward gradually decelerating to the downward gravitational acceleration until they reaches the peak of the jump (zero velocity). Then, back to Earth.