Question

950 kg
3.
If the car has 30.400 J of kinetic
energy, how fast is it moving?

Answer 1

m
=
950

k
g
E
=
30
,
400

J
To determine the speed of the car, we use the term for kinetic energy:

E
=
1
2
m
v
2

and we re-arrange this equation to get the speed v:

v
=
√
2
E
m

and we substitute:

v
=
√
2
(
30
,
400

J
)
950

k
g

evaluating this, we obtain the speed:

v
=
8

m
/
s