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 84.0-kg water-skier has an initial speed of 7.4 m/s. Later, the speed increases to 12.3 m/s. Determine the work done by the net external force acting on the skier.

Net work = 4054.26J

Explanation:

We are given that;

mass of water-skier; m= 84 kg

Initial speed; v_i = 7.4m/s

Final speed v_f= 12.3 m/s

Kinetic energy of mass moving with velocity is; KE = (1/2)mv²

From work energy theorem, the net work done on an object is equal to the difference between the initial and final kinetic energy of that object.

Thus,

W = KE_f - KE_i

W = (1/2)mv_f² - (1/2)mv_i²

Plugging in the relevant values to get ;

W = (1/2)(84)(12.3²) - (1/2)(84)(7.4)²

W = 4054.26J

the correct choice is a .

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unbalanced force

explanation: