Question

A car moves in a straight line at a speed of 62.0 km/h.

(a)
How far (in kilometers) will the car move in 2.00 minutes at this speed?

km
(b)
How long (in seconds) will it take the car to move 0.25 km at this speed?

s

Answer 1

(a) 2.065 km

(b) 14.52 seconds

Step-by-step explanation:

We know that the speed of the car is:

`62.0\ (km)/(h)`

This means that in one hour the car travels 62 km.

To know the distance it travels in two minutes then we write 2 minutes in units of hours.

1 hour = 60 minutes.

So

`2\ minutes*(1\ hour)/(60\ minutes)=0.0333\ hour`

Now multiply 0.0333 hours by speed:

`0.0333\ h\ *62.0\ (km)/(h)=2.065\ km`

(a) How far (in kilometers) will the car move in 2.00 minutes at this speed?

2.065 km

Now we calculate how long it will take the car to travel 0.25 km

Remember that:

`Speed = (distance)/(time)` and
`time = (distance)/(speed)`

Therefore:

`t=(0.25\ km)/(62\ (km)/(h))\\\\t=0.00403\ h`

To convert this amount to seconds perform the following operation

`0.00403\ h * (60\ minutes)/(1\ h)*(60\ seconds)/(1\ minute) =14.52\ second`

(b) How long (in seconds) will it take the car to move 0.25 km at this speed?

14.52 seconds