Question

E. A racing car has a mass of 710kg. It starts from rest and travels 120m in

Answer 1

6300
N

Explanation:
We will employ the following equation of kinematics
x
=
1
2
a
t
2

which describes an object traveling in one dimension with a constant acceleration and an initial velocity of zero.
We know the displacement and the time elapsed so we may solve for the acceleration:
40.0
m
=
1
2
a
(
3.0
s
)
2

Solving for
a
yields:
a
=
8.89
m
s
2

Now, knowing the acceleration of the car as well as the mass of the car we can apply Newton's second law, which states
F
net
=
m
a

All we need to do is plug in our values for
m
and
a
:
F
net
=
710
kg
⋅
8.89
m
s
2
=
6311.9
N

Considering the fact that our final answer should have only two significant digits, we will round to the nearest hundred:
F
net