Law of Acceleration Grade 8

1. Each of the items below is best
represented by Newton’s First Law of
Motion-LAW OF INERTIA. Give a short
explanation on why each situation applies
the Law of Inertia.
1. When you are standing in a subway
train, and the train suddenly stops,
your body continues to go forward.
2. A grocery cart is sitting motionless in
the parking lot at Wal-Mart. You decide
to jump in and your friend pushes you
around.

2. 5kg
A
B
 Who is pushing
very hard?
 Why things
speed up or
slow down?

5. Acceleration is when the
motion of an object changes.
Example:
speeds up
slows down
changes direction

6. The second law states that the
acceleration of an object is
dependent upon two variables:
• the net force acting upon the
object
• mass of the object

7. Which requires greater force
to make it move: the
elephant or the ball?

8. The greater force is needed
to cause a change in speed in
an object with a greater
mass.

9. Small amount of force is needed to make
a small mass to move.
Mass – quantity of matter an object contains.

10. “The acceleration of an object
is directly proportional to the
magnitude of the net force
acting on it but inversely
proportional to its mass.”

11. When the mass is kept constant, the
greater the force, the greater the
acceleration.
Which door will move faster?

12. If the force applied is the same, the
greater mass will travel less distance
or slower, while the lesser mass will
travel a greater distance or faster.
10 N
10 N

13. 5N 5N
10kg
5N
10kg
When an object speeds up, it ACCELERATES,
and if it slows down, then it DECELERATES.

14.  In equation:
1N = 1kg.m/s2
a = Acceleration measured in
meter/second square (m/s2)
F = Force measured in Newton (N)
m = Mass measured in Kilograms (kg
a =
F
m

15.  Suppose a ball of mass .60 kg is hit
with a force of 12 N. Its acceleration
will be:
Given: F = 12 N m = 0.60 kg a=?
a =
a =
F
m
12 kg m/s2
0.60 kg
a = 20 m/s2

16. A formula triangle helps you to rearrange a formula. The
formula triangle for force (f), mass (m) and acceleration (m)
is shown below.


x
Cover the quantity that you are trying to work out, which
gives the rearranged formula needed for the calculation.
So to find force (f),
cover up f…
…which gives
the formula…
f = m x a

17. A motorcycle experiences a net
force of 2000N. What is the
acceleration if the mass of the
motorcycle is 500kg?
Given : m =
F =
Find: a = ?

18. How much force is needed to
accelerate a 1400 kg car at 2
m/s2?

20. Explain the following by
applying the Law of
Acceleration.
 It is much easier to carry your
backpack when it is empty
rather than when it is full of
textbooks.

21. 1. If mass remains constant, doubling the force,
_________ the acceleration.
2. If force remains constant, doubling the mass,
_________the acceleration.
5
10
4
50
9.8
1000
double
halves

22. Complete each statement by filling in the
blanks with the correct answer.
Newton’s second law of motion is also known
as __________________________________.
Newton’s second law says that when an
________________ force is applied to an
________________, it causes it to
________________________. The greater the
force that is applied, the _________________
the acceleration. The lesser the force that is
applied, the _________________ the
acceleration.
(1)
(2)
(3)
(4)
(5)
(6)

23. If the same force is applied to an object with
a large mass, it will have _________________
acceleration. If the same force is applied to
an object with a small mass, it will have
_________________ acceleration.
The equation that is used to solve second law
problems is ________.
What does each of the variables mean?
F = ______ m = _________ a = __________
What UNIT of measurement must be used
with each variable?
F = ______ m = ______ a = ______
(7)
(8)
(9)
(10) (11) (12)
(13) (14) (15)

24. Complete each statement by filling in the
blanks with the correct answer.
Newton’s second law of motion is also known
as __________________________________.
Newton’s second law says that when an
________________ force is applied to an
________________, it causes it to
________________________. The greater the
force that is applied, the _________________
the acceleration. The lesser the force that is
applied, the _________________ the
acceleration.
(1)
(2)
(3)
(4)
(5)
(6)
Law of Acceleration
unbalanced
object
accelerate
greater
lesser

25. If the same force is applied to an object with
a large mass, it will have _________________
acceleration. If the same force is applied to
an object with a small mass, it will have
_________________ acceleration.
The equation that is used to solve second law
problems is ________.
What does each of the variables mean?
F = ______ m = _________ a = __________
What UNIT of measurement must be used
with each variable?
F = ______ m = ______ a = ______
(7)
(8)
(9)
(10) (11) (12)
(13) (14) (15)
lesser
greater
a = F
m
force mass acceleration
N kg m/s2

26. 1. The driver of a 1125kg dump truck
exerts a sudden brake with a force
2500N. Calculate the acceleration
of the truck upon the sudden
brake.
2. A net force of 16 N causes a mass
to accelerate at a rate of 5 m/s2.
Determine the mass of the object.