Question

At highway speeds, a particular car is capable of an acceleration of about 1.6 m/s?. At this rate,

does it take the car to speed up from 80 km/hr to 110 km/hr? Round your answer to
Two significant figures

Answer 1

Given parameters:

Acceleration of the car = 1.6m/s

Initial speed = 80km/hr

Final speed = 110km/hr

Solution:

Time taken to achieve this speed = ?

Solution:

Acceleration is the rate of change of velocity with the time taken.

Mathematically;

a =
`(V - U)/(T)`

where a is the acceleration

V is the final velocity

U is the initial velocity

T is the time taken

Now make the unknown time the subject of the expression;

aT = V - U

T =
`(V - U)/(a)`

Convert the given acceleration to km/hr;

1.6m/s = 1.6 x
`(m)/(s)` x
`(1km)/(1000m)` x
`(3600s)/(1hr)` = 5.76km/hr

Input the parameters and solve;

T =
`(110 - 80)/(5.76)` = 5.2hrs

The time taken is 5.2hrs