Q 56

A champion athlete can produce one horsepower (746 W)for a short period of time.If a 70-kg athlete were to bicycle to the summit of a 500-m high mountain while expending power at this rate,she would have used at least ____ J of energy.
A)746
B)3.43 10^{5}
C)3.73 10^{5}
D)7.46 10^{5}
E)2.61 10^{7}

Q 57

A champion athlete can produce one horsepower (746 W)for a short period of time.If a 70-kg athlete were to bicycle to the summit of a 500-m high mountain while expending power at this rate,she would reach the summit in ____ seconds.
A)1
B)460
C)500
D)1 000
E)35 000

Q 58

Jane and Jake are looking at what happens to body 1 of mass m and body 2 of mass 2m,initially at rest,when equal forces are applied separately to the two bodies.Jake says that equal forces applied for equal times do equal amounts of work on the two bodies.Jane says that the two forces do equal amounts of work only if the two bodies move equal distances in the direction of the forces.Which one,if either,is correct?
A)Jake,because the speed of body 1 is half the speed of body 2,but m_{1}v_{1} = m_{2}v_{2}.
B)Jane,because work does not depend on mass,only on force times distance.
C)Jake,because all bodies travel equal distances when equal forces are applied for equal times.
D)Jane,because it takes the same time for all bodies to travel equal distances when equal forces are involved.
E)Neither,because we can't compare the amounts of work done on bodies of different mass.