Download Quiz on Motion under gravity

Motion under gravity
Name:___________________________ (
)
Date: ___________
---------------------------------------------------------------------------------------------------------Section A: For each question below, write the letter corresponding to the correct
response in the space at the end of this section.
1.
Which one of the following speed-time graphs represents the motion of
an object being thrown vertically upwards and returning to the ground
before rebounding?
2.
The speed -time graph shown represents
the motion of a ping-pong vertically
downward in air. The net force acting on
the ping-pong
A
B
C
D
3.
speed
decreases and then increases
increases and then decreases
decreases to zero
remains constant with time
0
time
An object is projected vertically upwards from the ground. Which of the
following graphs correctly shows the variation of the height h reached by
the object with time t?
A
B
h
h
0
t
C
D
h
0
t
1
0
h
t
0
t
4.
An object is thrown vertically upward with an initial speed. The
acceleration due to gravity is 10 m/s2. At the highest point of its motion,
the magnitude and direction of its acceleration are respectively
A
B
C
D
5.
A boy throws a stone vertically upwards with a speed of 10 m/s. What is
the acceleration of the stone one second after leaving the boy's hand?
A
B
C
D
6.
acceleration
distance travelled in 1 s
speed
velocity
What must be changing when a body is accelerating uniformly?
A
B
C
D
8.
0 m/s2
5 m/s2 downwards
10 m/s2 downwards
10 m/s2 upwards
A ball is falling freely (with no air resistance) near the surface of the Earth.
Which quantity remains constant?
A
B
C
D
7.
10 m/s2 and downward
10 m/s2 and upward
zero and upward
zero and downward
The force acting on the body
the mass of the body
the speed of the body
the velocity of the body
Why does an object falling from a great height in the Earth’s gravity field
reach a steady velocity?
A
B
C
D
Air resistance increases with increase in velocity
The Earth’s gravitational field decreases as the object falls
The mass of the object remains constant
The weight of the object remains constant as it falls.
2
9.
Which of the following statements is/are true about an object thrown
upwards and drops down to the original level?
I
II
The acceleration of the object decreases as the object rises up;
The acceleration is positive for the upward motion and negative for
the downward motion;
At maximum height, the velocity of the object is zero;
If air resistance is negligible, the time for the upward motion is
equal to the time for the downward motion
III
IV
A
B
C
D
I, II & III
II, III & IV
III & IV
IV
Answers for Section A:
1
2
3
4
5
6
7
8
9
Section B:
10.
A small steel ball, dropped from rest, takes 0.50 s to fall through a vertical
distance of 1.25 m. Determine:
a.
b.
c.
the average speed of the ball,
the actual speed of the ball when it has fallen through a vertical
distance of 1.25 m, assuming that the acceleration is constant,
the value of the acceleration.
3