Question

A convertible is traveling at 45 miles per hour, and its wheels have a diameter of 48 inches. How many complete revolutions do the wheels make in one minute?

Answer 1

To answer this question you will need to know how many inches the car travels Per minute.

1. To find this out you will first divide 45 miles by 60 to get the number of miles per minute.

The convertible travels 0.75 mi./min.

2. Next you will convert this number of miles to inches.

There are 63,360 inches per mile.

0.75 x 63360 = 47520 inches per minute.

3. You then need to find the distance the wheel travels in one rotation. You will need to find the circumference of the wheel.

C = pi x d
3.14 x 48
C = 150.72 inches
Each rotation is about 150.72 inches.

4. Finally, divide the total distance traveled in a minute by the circumference(distance of one rotation) to get the total number of rotations in a minute.

47520/150.72 is about 315.3 rotations per minute.

Answer 2

Answer: The wheel make 315 complete revolutions in one minute

Step-by-step explanation: Given speed of convertible =45 miles/hr

Firstly we will convert miles to inches

We know that 1 mile= 63360 inches

So 45 miles= $45 \times63360$

i.e. speed=2851200 inches/hr

Now since the revolutions are asked in one minute

So speed= $\frac{2851200}{60}$

=47520 inches/min

Now In one revolution distance travelled by wheel=2πr or πd

=$3.14\times 48$

=150.72 inches

No of revolutions =Total distance travelled/Distance travelled in one revolution

=$\frac{47520}{150.72}$

=315.28 revolutions