# Shopping cart problem help

1. Sep 11, 2009

### Mirole

1. The problem statement, all variables and given/known data
Jill has just gotten out of her car in the grocery store parking lot. The parking lot is on a hill and is tilted 3 degrees. Fifty meters downhill from Jill, a little old lady lets go of a fully loaded shopping cart. The cart, with frictionless wheels, starts to roll straight downhill. Jill immediately starts to sprint after the cart with her top acceleration of 2.0m/s^2.

2. Relevant equations

3. The attempt at a solution
a(cart)=g*sin3=.51m/s^2

I know I need to use two equations to find the solution, but I am utterly confused on which two to use.
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Sep 11, 2009

### tiny-tim

Welcome to PF!

Hi Mirole! Welcome to PF!
Use the usual https://www.physicsforums.com/library.php?do=view_item&itemid=204" equations, but use s in one and s + 50 in the other.

Last edited by a moderator: Apr 24, 2017
3. Sep 14, 2009

### Mirole

Re: Welcome to PF!

I went:

S(1) = 1/2*a(j)*t^2
S(2) = 50 + 1/2*a(cart)*t^2

I set them equal to each other.

1/2*a(j)*t^2 = 50 + 1/2*a(cart)*t^2

1/2*2*t^2 = 50 + 1/2*.51*t^2
Cross off the t^2s.

1=50+1/2*.51
1=50.255

That's obviously not right, and this problem has given me a mental block. :(

Last edited by a moderator: Apr 24, 2017
4. Sep 14, 2009

### tiny-tim

Hi Mirole!

(try using the X2 tag just above the Reply box )
"Cross off the t^2s" ??

get some sleep! :zzz:​