# Linear speed and magnitude of linear acceleration

1. Oct 23, 2013

### Hambone12

1. The problem statement, all variables and given/known data

A car with 64.0-cm-diameter tires is being driven down a level road at 75.0 km/hr. As seen by a person riding in the car (i.e. relative to the passenger), what are the linear speed and magnitude of the linear acceleration of a) the center of one of one of the wheels, b) a point at the top of the tire, c) a point at the bottom of the tire? For parts d), e), and f) answer the same questions for an observer standing on the side of the road.

2. Relevant equations

v=ωr

3. The attempt at a solution

So I found the rotational velocity of the wheels by using the previous equation. I am getting confused on ultimately where to even start the problem from, yet alone calculating the values from both observations. If anyone could offer some input on the next couple steps that would be greatly appreciated.

2. Oct 23, 2013

### nasu

Which one of the questions are you talking about? For (a) you don't need this formula. It's only about linear quantities. How does the center of the wheel moves relative to the car?