Tortoise and Hare w Solution A tortoise and hare start from rest and have a race
ID: 3280523 • Letter: T
Question
Tortoise and Hare w Solution A tortoise and hare start from rest and have a race. As the race begins, both accelerate forward. The hare accelerates uniformly at a rate of 0.8 m/s2 for 4.3 seconds. It then continues at a constant speed for 13.1 seconds, before getting tired and slowing down with constant acceleration coming to rest 56 meters from where it started. The tortoise accelerates uniformly for the entire distance, finally catching the hare just as the hare comes to a stop. How fast is the hare going 1.3 seconds after it starts? See solution 1.04 2How fast is the hare going 12.2 seconds after it starts? See solution 3.44 How far does the hare travel before it begins to slow down? See solution 52.5 What is the acceleration of the hare once it begins to slow down? See solution What is the total time the hare is moving? See solution 19.46 What is the acceleration of the tortoise? See solution 0.30 Your submissions: 0.30 x Computed vallue: 0.30 Submitted: wednesday, October 11 at 8:36Explanation / Answer
since tortise and hare start from rest their initial velocities are zero i.e Vo=0
a)
from
V=Vo+at
at t=1.3 s
V=0+0.8*1.3
V=1.04 m/s
b)
upto t=4.3 s
V=0+0.8*4.3=3.44 m/s
after 4.3 s it goes at constant speed for another 13.1 s ,therfore at t=12.2 s
V=3.44 m/s
c)
Total distance travelled before slowing down
D=(1/2)*0.8*4.32+13.1*3.44=52.46
d)
distance cover during deceleration
d=56-52.46=3.54 m
from V2=Vo2+2ad
0=3.442+2*a*3.54
a=-1.67 m/s2
e)
time taken to slow dowm
t=V/a=3.44/1.67=2.06 s
total time
T=4.3+13.1+2.06
T=19.46 s
f)
from
S=Vot+(1/2)at2
56=0+(1/2)*a*19.462
a=0.296 m/s2