Astudent wearing frictionless in-line skates on a horizontal surface is pushed by a friend with a constant force of 47 n. how far must the student be pushed, starting from rest, so that her final kinetic energy is 354 j ?

7.53 m

Explanation:

Force, F = 47 N

initial velocity, u = 0

Final kinetic energy, Kf = 354 J

Let the distance traveled by the student is s.

According to the work energy theorem,

Work done by all forces = Change in kinetic energy

Force x distance = final kinetic energy - initial kinetic energy

F x s = kf - ki

47 x s = 354

s = 7.53 m

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min