A fast tortoise runs with a speed of 10.0 cm/s and a hare runs 20.0 times faster
ID: 2137377 • Letter: A
Question
A fast tortoise runs with a speed of 10.0 cm/s and a hare runs 20.0 times faster. They start a race together but the hare stops to rest for 2.00 minutes. The tortoise wins by 20.0 cm. (a) How long (time) is the race? (b) What distance did the hare cover? A fast tortoise runs with a speed of 10.0 cm/s and a hare runs 20.0 times faster. They start a race together but the hare stops to rest for 2.00 minutes. The tortoise wins by 20.0 cm. (a) How long (time) is the race? (b) What distance did the hare cover?Explanation / Answer
a) tortoise runs for the full time of race = t sec
hare runs for t-(2*60 )sec
distance tracelled by tortoise = speed *time = 10*t cm
distance travelled by hare = 200*(t-(2*60)) cm
difference = 20 cm
=> 10*t - 200*(t-(2*60)) = 20
=> 10t - 200t +2*60*200 = 20
=> t = 126.210526 sec ans(a)
distance travelled by hare = 200*(126.210526-(2*60)) = 1242.1052 cm ans(b)