A movie stunt double is supposed to run across the top of a train (in the opposite direction that the train is moving) and just barely jump off before reaching a tunnel, but after reaching the end of the train (starting from the front). If the train is moving at 150 km/hr, is 2 km long and the tunnel is 20 km away from the end (where the stunt double is going to jump from), how fast (in km/hr) will the stunt double need to run

the required speed/velocity of the stunt double is 13.633 km/h

Explanation:

Given the data in the question;

velocity of train V = 150 km/h

distance = length of train + distance between the tunnel and the end

= 2 km + 20 km = 22 km

first we calculate time t taken by the train to reach the tunnel;

t = distance / velocity

we substitute

t = 22 km / 250 km/h

t = 0.1467 hr

so the velocity of the of the stunt double will be;

velocity = distance / time

we substitute

velocity = 2 km / 0.1467 hr

velocity = 13.633 km/h

Therefore, the required speed/velocity of the stunt double is 13.633 km/h

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.

well, you would divide 135 by 33 to get your answer. then that is how many seconds it would take. boardman should fly about 132 m or 4.090909090909091 seconds.