physics
posted by kris .
A tortoise can run with a speed of 0.12 m/s, and a hare can run 20 times as fast. In a race, they both start at the same time, but the hare stops to rest for 1.0 minutes. The tortoise wins by a shell (30 cm).
(a) How long does the race take?
(b) What is the length of the race?

(a) Re

Sorry, my computer is acting up.

Write equations for distances travelled vs time for each animal. Assume the hare pauses once, for 60 seconds, during the race.
Set the distance travelled by the tortoise (X1) equal to the distance travelled by the hare (X2) PLUS 0.3 meters.
X1 = 0.12 t meters
X2 = 2.4 (t  60)
X1  X2 = 0.12t 2.4t + 144 = 0.3
Solve for t.
143.7 = 2.28 t
t = 63.026 seconds
Using that t, compute X1(t)
X1 = 7.563 m
X2 = 7.263 m 
A motor car moving at a speed of 72 km/h can not come to a stop in less than 3 s while for a truck this time interval is 5.0s . On a highway the car is behind the truck both moving at 72 km/h . The truck gives a signal that it is going to stop at emergency. At what distance the car should be from the truck so that it does not bump onto the truck . Human response time is 0.5s
Respond to this Question
Similar Questions

Physics
A tortoise can run with a velocity of 10 cm/s and hare can run 20 times as fast. In a race they start at the same time but the hare stops to rest for 2 minutes. The tortoise wins by 20 cm. What was the length of the race 
physic
Hi, could you help me please Question: A tortoise can run with a speed of 0.12 m/s and a hare can run 20 times as fast. in a race, they both start at the same time, but the hare stops to rest for 2.0 minutes. The tortoise wins by a … 
college
A tortoise can run with a speed of 0.10m/s and a hare can run 20 times as fast. In a race, they start at the same time, but the hare stops to rest for 2.0min. The tortoise wins by a shell (20cm). How long does the race take? 
Physics
A tortoise can run at a speed of 20 cm/s and a hare can run exactly 20 times as fast. In a race, they both start at the same time but the hare stops to rest for 2.00 mins. The tortoise wins by 20.0 cm. How long does the race take? 
please someone answer this question
A tortoise can run with a speed of 16.0 cm/s, and a hare can run exactly 25 times as fast. In a race, they both start at the same time, but the hare stops to rest for 2.00 min. The tortoise wins by 20.0 cm. (a) How long does the race … 
Physics
A tortoise can run with a speed of 10.1 cm/s, and a hare can run 19.4 times as fast. In a race, they both start at the same time, but the hare stops to rest for 122 seconds. The tortoise wins by a shell (20.8 cm). How long does the … 
physics
A tortoise can run with a speed of 11.5 cm/s, and a hare can run 21.4 times as fast. In a race, they both start at the same time, but the hare stops to rest for 126 seconds. The tortoise wins by a shell (18.3 cm). How long does the … 
Physics
A tortoise can run with a speed of 0.13 m/s, and a hare can run 20 times as fast. In a race, they both start at the same time, but the hare stops to rest for 4.0 minutes. The tortoise wins by a shell (35 cm). (a) How long does the … 
Physics
A tortoise can run with a speed of 14.0 cm/s, and a hare can run exactly 15 times as fast. In a race, they both start at the same time, but the hare stops to rest for 2.00 min. The tortoise wins by 20.0 cm. (a) How long does the race … 
physics
A speedy tortoise can run at 0.12 m/s, and a hare can run 18 times as fast. In a race, they start at the same time, but the hare stops to rest for 1.5 min, so the tortoise wins by a shell (20 cm). How long does the race take?