Question

A young woman on a skateboard is pulled by a rope attached to a bicycle. The velocity of the skateboarder is v = (4.1m/s )x and the force exerted on her by the rope is F= (17N )x + (12N )y. A. Find the work done on the skateboarder by the rope in 20 seconds B. Assuming the velocity of the bike is the same as that of the skateboarder, find the work the rope does on the bicycle in 20 seconds

Answer 1

Answer:

Explanation:

Given

velocity of skateboarder is 4.1 m/s

Force $F_x=14,F_y=12 N$

time=20 s

As the motion is along x axis therefore

Power $=F\cdot v$

Power$=14\times 4.1=57.4 Watt$

only x component of force comes into play because there is no motion in Y direction.

Work done will be$=P\times t=57.4\times 20=1148 J$

Work done on skate boarder by rope is 1148 J

and work done on bicyclist by rope is -1148 as the direction of velocity is opposite to applied force