A shopper in a supermarket pushes a loaded cart with a horizontal force of 13.3 Newtons. The cart has a mass of 25.1 kg and is pushed for 3.60 seconds, starting from rest?
(a) How far (in meters) will the cart move during these 3.60 seconds. (Ignore friction.)
m



(b) How far (in meters) will the cart move in the 3.60 second interval if the shopper places her 27.4-N child in the cart before she begins to push it?
m




Answer :

Ewan
a) S(displacement)=ut+1/2at^2  a=f/m
 thus s=1/2(13.3/25.1)(3.6)^2   ut dissapear because u=0
s=3.43m

b) the inertia has increased because the mass increases:
m(kart+child)=(245.98+27.4)/9.8
m=27.896
s=ut+1/2at^2
s=1/2(13.3/27.899)(3.6)
s=3.09m