Question

In 1967, New Zealander Burt Munro set the world record for an Indian motorcycle, on the Bonneville Salt Flats in Utah, with a maximum speed of 183.58 mi/h. The one-way course was 5.00 mi long. Acceleration rates are often described by the time it takes to reach 60.0 mi/h from rest. If this time was 4.00 s, and Burt accelerated at this rate until he reached his maximum speed, how long did it take Burt to complete the course ?

Answer 1

Answer:49 sec

Step-by-step explanation:

Given

Maximum speed to reach is 183.58 mi/h

Length of course is 5 mi

acceleration rate is defined by 60mi/h in 4 sec

therefore acceleration(a)$=\frac{v-u}{t}$

$a=\frac{60\times 60\times 60}{4}$

$a=54\times 10^3 mi/h^2$

To reach a speed of 183.58mi/h with an acceleration of $54\times 10^3 mi/h^2$

Using equation of motion

v=u+at

$183.58=0+(54\times 10^3)t$

$t=\frac{183.58}{54\times 10^3}$

t=0.00339 hours

t=12.23 s reach maximum speed

To complete course it takes

$s=ut+\frac{1}{2}at^2$

$5=0+\frac{1}{2}\times 54\times 10^3 \times t^2$

t=0.01360 hour

or $t=48.98\approx 49 s$