Help with physics please!?

Question

A 94.0 N grocery cart is pushed 12.0 m along an aisle by a shopper who exerts a constant horizontal force of 40.0 N. If all frictional forces are neglected and the cart starts from rest, what is the grocery cart's final speed?
m/s

Answer 1

Take g = 9.8m/s^2

Mass of cart (m) = 9.6 kg (Weight/g = mass)
s = 12 m
Force on cart (F) = 40 N
Initial velocity (u) = 0 m/s

Let acceleration of cart be a and its final velocity be v.

F = ma
40 = 9.6*a
a = 40/9.6

v^2 - u^2 = 2as
v^2 = 960/9.6
v^2 = 100
v = 10m/s

The cart's final speed is 10m/s (or) 36 km/h

Answer 2

Kia ora

Concept: a force applied over a distance does work. Work is the conversion of energy.

Relationships: Work = force * distance; kinetic energy is Ek = ½mv²; mass = weight/g

So you find the work done:
W=Fd=40.0*12.0=480 Joules

This is the gain in Ek; since the cart starts from rest, initial Ek is zero so final Ek is 480 Joules.

480=½mv²
v²=480/(½m)
v=√(480/4.8)=10 m/s

Answer 3

F=ma
F=40 N
Mass = 94/9.8

40 =94/9.8 X a
a= 4.170212766 ms^-2

V^2=2as+U^2
V^2=2(4.170212766)(12.0)
V=10.0 ms^-1