A water-skier is being pulled by a tow rope attached to a boat. As the driver pushes the throttle forward, the skier accelerates. A 73.0-kg water-skier has an initial speed of 7.1 m/s. Later, the speed increases to 10.9 m/s. Determine the work done by the net external force acting on the skier.
A= KE2 - KE1= (mv2^2)/2 - (mv1^2)/2 =2058.6 J.
To determine the work done by the net external force acting on the water-skier, we need to use the work-energy principle. According to this principle, the work done on an object is equal to the change in its kinetic energy.
The kinetic energy (KE) of an object can be calculated using the formula:
KE = (1/2) * m * v^2
where m is the mass of the object and v is its velocity.
First, we can calculate the initial kinetic energy of the skier using the given values:
m = 73.0 kg (mass of the skier)
v(initial) = 7.1 m/s (initial speed of the skier)
KE(initial) = (1/2) * m * v(initial)^2
= (1/2) * 73.0 kg * (7.1 m/s)^2
Next, we calculate the final kinetic energy of the skier:
v(final) = 10.9 m/s (final speed of the skier)
KE(final) = (1/2) * m * v(final)^2
= (1/2) * 73.0 kg * (10.9 m/s)^2
Finally, we find the work done by subtracting the initial kinetic energy from the final kinetic energy:
Work done = KE(final) - KE(initial)
Now you can plug in the values into the equation and calculate the work done by the net external force acting on the skier.