Practice Questions

Question 1

What is the unit moment of force?
a) N
b) Nm
c) N*m
d)N^m

Answer 1

b) Nm

Question 2

A slice of bread is squeezed into a little ball. Which quantity does NOT change?
(a) Volume
(b) Mass
(c) Density
(d) Width

Answer 2

b) Mass

When you squeeze a loaf of bread, the mass does not change. The volume on the other hand does change. It becomes smaller, and when you decrease the volume of an object, the density increases

Question 3

Power can be defined as
(a) force × distance moved
(b) force ÷ time
(c) work done ÷ time
(d) work done × time

Answer 3

c) Work done /time

Question 4

4. An atom that gains an electron is called
   (a) a positive ion
   (b) a negative ion
   (c) a neutral ion
   (d) none of the above

Answer 4

b) a negative ion

Question 5

5. If the resultant force on an object is zero, the object will move with
   (a) decreasing velocity
   (b) constant velocity
   (c) constant acceleration
   (d) increasing velocity

Answer 5

b)Constant velocity

Question 6

6.If force = mass × acceleration then the unit of force could be written:

Answer 6

1 Newton = 1 kg * m/s2

Question 7

Choose the TWO (2) examples of fundamental/base quantity.

(a) Mass and density
(b) Length and mass
(c) Length and area
(d) Mass and velocity

Answer 7

b) Length and Mass

Question 8

The International System (SI) of time is:
(a) second (s)
(b) minute (min)
(c) hour (hr)
(d) millisecond (ms)

Answer 8

a) second

Question 9

Which physical quantity is not a base quantity?
(a) Time
(b) Length
(c) Weight
(d) Electric Current

Answer 9

c) Weight

Question 10

10. A book weighing 120 N is resting on a table. The force that the table exerts on the book is
    (a) zero N
    (b) greater than zero N but
    less than 120 N
    (c) 120 N
    (d) greater than 120 N

Answer 10

c) 120N

Newton’s third law of motion states that for every action, there is an equal and opposite reaction12. This means that whenever two objects interact, they exert equal force.

Question 11

11. Which of the following are units?
    (a) Work
    (b) Density
    (c) Force
    (d) Watt

Answer 11

d. Watt

Question 12

Calculate the work done when a force of 200N moves an object a
distance of 3m?
(a) 40 J
(b)600 J
(c) 1000 J
(d)2000 J

Answer 12

b) 600 J

Question 13

When an astronaut is standing
on the moon, his mass is 70 kg.
When he returns to earth his
approximate weight will be:

a) 70 Kg
b) 420 Kg
(c) 70 N
(d) 700 N

Answer 13

a) 70kg

Question 14

What type of force is shown in a tug of war?
(a) Tensional force
(b) Contact force
(c) Both
(d) None

Answer 14

a) Tensional force

Question 15

Gravity is the force of ______________________ between any two objects that have ______________________. The strength of the attractive force depends on two things, the mass of the objects and the
____________________ they are from each other.

Answer 15

Gravity is the force of ATTRACTION between any two objects that have MASS. The strength of the attractive force depends on two things, the mass of the objects and the
DISTANCE they are from each other.

Question 16

The mass of the Earth is six times the mass of the moon, because of this the Earth exerts _____________________ times the gravitational pull of the moon. Weight is a measure of ____________________, whereas mass is a measure of the amount of ___________________ in an object. If an object weighs 60N on Earth, it would weigh __________________N on the moon. _____________________ are used to represent forces. The arrows tell us two things about the force, it tells us the __________________ of the force and the ____________________ of the force.

Answer 16

The mass of the Earth is six times the mass of the moon, because of this the Earth exerts EIGHTY times the gravitational pull of the moon. Weight is a measure of THE FORCE OF GRAVITY whereas mass is a measure of the amount of MATTER in an object. If an object weighs 60N on Earth, it would weigh 10N on the moon. ARROWS are used to represent forces. The arrows tell us two things about the force, it tells us the PUSH of the force and the PULL of the force.

The weight of an object on the moon is much less than its weight on Earth because the moon has less gravity than Earth. The formula to calculate weight on the moon is to divide weight on Earth by 9.81 and multiply by 1.622 1.

So if an object weighs 60N on Earth, it would weigh 9.79N on the moon (60/9.81*1.622) 1.