Q1. Choose the correct option. 10×1=10
1
When we kick a stone, we get hurt. This is due to:
A
Inertia
B
Velocity
C
Momentum
D
Reaction
2
Conservation of linear momentum is equivalent to:
A
Newton’s first law of motion
B
Newton’s second law of motion
C
Newton’s third law of motion
D
None of these
3
What is the formula of gravitational force?
A
F = G m₁ m₂ / d²
B
F = G m₁ / d²
C
F = m₁ m / d²
D
F = G m₁ / d²
4
What is the term for the product of an object’s mass and velocity?
A
Momentum
B
Inertia
C
Friction
D
Gravity
5
How does the weight of an object change when it is taken to a different planet?
A
It remains the same
B
It increases
C
It decreases
D
It depends on the mass of the planet
6
What opposes the motion?
A
Gravity
B
Friction
C
Magnetism
D
Electricity
7
Friction effects:
A
Speed
B
Direction
C
Both
D
Neither
8
Momentum is a:
A
Scalar quantity
B
Vector quantity
C
Both A and B
D
Neither A nor B
9
Condition for conservation of momentum is:
A
Open system
B
Closed system
C
Moving object
D
Stationary object
10
What happens to total momentum in a closed system?
A
Increase
B
Decrease
C
Remains constant
D
Become zero
Q2. Write down short answers of following questions. 15×2=30
I
When sitting in a car which suddenly accelerates from rest, you are pushed back into the seat, why?
II
Define terminal velocity of an object.
III
What is the force between two objects in motion?
IV
Differentiate between air resistance and tension force.
V
What is electrostatic force?
VI
Prove that F = ma
F = m × a
VII
What is the unit of force in the SI system?
VIII
What type of force is required to change the motion of an object?
IX
What is the unit of mass in the SI system?
x
Can the weight of an object change?
xi
What are the different types of friction?
xii
What factors affect friction?
xiii
Why is friction important in our daily life?
xiv
What is the unit of momentum?
xv
Can momentum be conserved in an open system?