A car of mass 1200 kg travelling at 72 km/h is brought to rest in 80 meters.(a) Find the average braking force on the car.
(b) What has happened to the original kinetic energy?
Answers
Explanation:
Equations of Kinematics and Newton's Second Law of Motion:
When a body moves with a constant acceleration, we can use the equation of kinematic to find variables in motion.
There are three main equations of kinematics under translational motion viz.,
v
t
=
v
i
+
a
t
.
.
.
(
i
)
S
t
=
S
0
+
v
i
t
+
1
2
a
t
2
.
.
.
.
(
i
i
)
2
a
S
=
v
2
t
−
v
2
i
.
.
.
.
.
.
(
i
i
i
)
Where;
a is the constant acceleration.
S is the distance traveled by the body.
v
t
is the speed of the body at time t.
v
i
is the initial speed of the body.
S
0
is the initial distance traveled by the object at t=0.
And,
The net external force applied on an object is the product of the mass of the object and the acceleration produced in it. It can be expressed as such;
F
e
x
t
=
m
a
Where a is the acceleration of the object.
Answer and Explanation:
Become a Study.com member to unlock this answer! Create your account
Given:
The mass of a car is
1200
k
g
.
The initial velocity of a car is
v
i
=
72.0
k
m
/
h
=
20.0
m
/
s
.
The final