Q1. Choose the correct option. 10×1=10
1
If a body does not change its position with respect to some fixed point, then it will be in a state of:
A
Rest
B
Motion
C
Uniform motion
D
Variable motion
2
Which of the following is a vector quantity?
A
Temperature
B
Mass
C
Velocity
D
Time
3
Which of the following is an example of vector quantity?
A
Displacement
B
Velocity
C
Acceleration
D
All of the above
4
Rest and motion are …… quantities.
A
Scalar
B
Vector
C
Relative
D
Absolute
5
Which of the following in an example of a body in motion?
A
A book lying a table
B
A car moving on a straight road
C
A person sitting on a chair
D
A tree standing in a field
6
Acceleration is a quantity:
A
Vector
B
Scalar
C
Both A and B
D
None of these
7
A speed-time graph can be used to determine the …… of an object:
A
Initial velocity
B
Final velocity
C
Average speed
D
All of above
9
What happens to velocity of a freely falling object?
A
Decrease
B
Increase
C
Constant
D
Become zero
10
What is the equation of freely falling object?
A
vf = vi + gt
B
2as
C
S = vit + ½at²
D
2as = vf2 – vi2
Q2. Write down short answers of following questions. 15×2=30
i
When a bullet is fired, its velocity with which it leaves the barrel is called the muzzle velocity of the gun. The muzzle velocity of one gun with a longer barrel is lesser than that of another gun with a shorter barrel. In which gun is the acceleration of the bullet larger? Explain your answer.
ii
Define mechanics and its branches.
iii
Define uniform velocity. Give example.
iv
Define acceleration. Write its formula and unit.
v
What is meant by deceleration?
vi
Define uniform acceleration. Give example.
viii
Describe the x-axis and y-axis of a speed-time graph.
ix
What does a curved line on a speed-time graph indicate?
x
What does the area under a speed-time graph represent?
xi
Describe how the area under a speed-time graph changes when an object accelerates?
xii
Describe the relationship between the area under a speed-time graph and the velocity of an object.
xiii
What is equation of motion under gravity for an object projected upward?
xiv
Write three equations of motion for bodies moving under gravity.
Write the three equations here…
xv
An eagle dives to the ground along a 300m path with an average speed of 60ms⁻¹. How long does it take to cover this distance?
Problem: Distance = 300 m, Average speed = 60 m/s