As a freely falling object picks up downward speed, what happens to the power supplied by the gravitational force?
1 answer:
We will start from the definition of power in terms of the Force. Power could be described as the change of energy in an instant of time. Considering that Energy is the product between the Force and the distance traveled we would arrive at the expression
Here,
F = Force
h = Height
t = Time
As there is no external force, apart from the force of gravity, and this, is constant during the course of the object we will also have to be constant power and therefore this during its course will be the same. The correct answer is (1)
You might be interested in
Answer:
Approximately to the right (assuming that both astronauts were originally stationary.)
Explanation:
If an object of mass is moving at a velocity of
, the momentum
of that object would be
.
Since momentum of this system (of the astronauts) conserved:
.
Assuming that both astronauts were originally stationary. The total initial momentum of the two astronauts would be since the velocity of both astronauts was
.
Therefore:
.
The final momentum of the first astronaut (,
to the left) would be
to the left.
Let denote the momentum of the astronaut in question. The total final momentum of the two astronauts, combined, would be
.
.
Hence, . In other words, the final momentum of the astronaut in question is the opposite of that of the first astronaut. Since momentum is a vector quantity, the momentum of the two astronauts magnitude (
) but opposite in direction (to the right versus to the left.)
Rearrange the equation to obtain an expression for velocity in terms of momentum and mass:
.
.
Hence, the velocity of the astronaut in question () would be
to the right.