The coefficient of friction between a racecar's wheels and the track is 1.0.The car starts from rest and accelerates at a constant rate for 400 m.Find the maximum speed at the end of the race.
A)44 m/s
B)66 m/s
C)89 m/s
D)99 m/s

Question

Quizplus · Accepted Answer

We can use the formula:
v^2=u^2+2as
where,
v = final velocity (maximum speed)
u = initial velocity (0 m/s)
a = acceleration (constant rate)
s = distance (400 m)
The acceleration can be calculated using the formula:
a = μg
where,
μ = coefficient of friction (1.0)
g = acceleration due to gravity (9.8 m/s^2)
a = 1.0 x 9.8 = 9.8 m/s^2
Now, substituting the values in the first formula, we get:
v^2 = 0^2 + 2 x 9.8 x 400
v^2 = 7840
v = sqrt(7840)
v = 88.6 m/s
Therefore, the maximum speed at the end of the race is 89 m/s (rounded off to one decimal place).

The Coefficient of Friction Between a Racecar's Wheels and the Track