Starting from rest, a 2.0 10-4-kg flea springs straight upward. While the flea is pushing off from the ground, the ground exerts an average upward force of 0.36 N on it. This force does +2.5 10-4 J of work on the flea.
-How far does the flea move while it's pushing off?
work = force * distance in direction of force
2.5*10^-4 = .36 x
x = 6.9*10^-4 meters
To find the distance the flea moves while pushing off, we can use the work-energy principle. According to the principle, the work done on an object is equal to the change in its kinetic energy.
In this case, the work done on the flea by the ground is +2.5 × 10^(-4) J. Since the flea starts from rest, its initial kinetic energy is zero.
The work done by a force is given by the formula:
Work = Force × Distance × cos(θ)
Where:
Work is the work done by the force (in Joules, J)
Force is the magnitude of the force (in Newtons, N)
Distance is the distance over which the force is applied (in meters, m)
θ is the angle between the force and the direction of motion (in degrees)
Since the force exerted by the ground is upward, the angle θ between the force and the direction of motion (upward) is 0°.
Rearranging the formula, we get:
Distance = Work / (Force × cos(θ))
Plugging in the given values:
Work = 2.5 × 10^(-4) J
Force = 0.36 N
θ = 0°
Distance = (2.5 × 10^(-4) J) / (0.36 N × cos(0°))
Now, let's calculate the distance.