Question

Help please? http://oi66.tinypic.com/2dtun9e.jpg

Answer 1

What did you get for a? We've already done a number of these centripetal force/acceleration problems, so you should be able to at least do that one!

Answer 2

15.27 m/s^2

Answer 3

@ganeshie8

Answer 4

Looks good to me. Now what do you know about the centripetal force for a car following a circular road? What do you think factors in to how the car stays on its circular path?

Answer 5

I know static friction is involved with the tires.

Answer 6

Yes, so the friction constitutes as the centripetal force. Some may disagree with it, but many textbooks and professors describe centripetal force to be fictitious. There's no actual force that is being acted upon an object that makes it follow a circular path out of the blue. It has to be due to another force. In this scenario, the friction has tributes and acts as the centripetal force. Now that we've conceptually stated that, we can mathematically say: \[\huge F_f=F_c\]Plug in both of the respective equations to each force and solve for \(\mu\)

Answer 7

Wouldn't I need the mass to solve for them? That's where I'm getting messed up. There isn't mass for me to look at.

Answer 8

Just plug in the equations and observe what happens when you solve for \(\mu\)

Answer 9

Which equations should I be using though?

Answer 10

Would you use Fstatic =Msf Fnorm?

Answer 11

Plug in each separate equation for F_f and F_c. There's a specific equation for each one. You just listed one of them.

Answer 12

Ac = V^2/R is the other one?

Answer 13

You just put the equation for acceleration. What's the equation for force F_c??

Answer 14

I don't think I know it. I'm not seeing it in my notes.

Answer 15

I gave it to you for the past 3 different problems. You already know it. It's the equation for centripetal force.

Answer 16

Fc=m V^2/r

Answer 17

@CShrix

Answer 18

Yes X) So now plug both equations into F_c=F_f and what do you get?

Answer 19

Fc=m V^2/r
Fc= m (29.5^2/57.0)=.518 N

Fstatic =Msf Fnorm?

Answer 20

\[\huge F_c=F_f \implies m\frac{v^2}{r}=\mu_s F_\text{normal}\]Looks good to me! Now just solve for \(\mu\)

Answer 21

Do you need to put anything for the m?

Answer 22

What's the normal force here, in terms of variables?

Answer 23

I'm getting confused on that.

Answer 24

What's the normal force here?