# Homework Help: Rotational motion of a car's tires

1. Mar 30, 2004

### ryanl

A car accelerates uniformly from rest and reaches a speed of 19.0 m/s in 7.00 s. The diameter of a tire is 64.0 cm.

(a) Find the number of revolutions the tire makes during this motion, assuming no slipping.

(b) What is the final rotational speed of a tire in revolutions per second?

How do I set this up?

Thank you.

2. Mar 30, 2004

### KSCphysics

just think abotu this one for a sec... its not too hard.. kinda basic ... have you tried it yet?

3. Mar 30, 2004

### Chen

Let's play 20 questions.

(a) Can you find the distance that the car travels during its acceleration? Can you find the perimeter of the tire? Can you tell how many times the perimeter fits inside the distance the car travelled?

(b) Do you know what the speed of a certain point on the tire is? Can you find how much time it takes that point to travel all around the tire and return to its original position? Can you now tell how many times it could do so in one second?