Section – A
1.
The driver of train A travelling at a speed of
54 kmh-1 applies brakes and retards
the train uniformly. The train stops in 5 seconds. Another train B is travelling on the parallel with
a speed of 36 kmh-1.
Its driver applies the brakes and the train retards uniformly; train B stops in 10seconds.
Plot speed-time graphs for both the trains on the same axis. Which of the
trains travelled farther after the brakes were applied?
2.
State which of the following situations are possible and give an example
for each of
these:
(a) an object with
a constant
acceleration but
with zero velocity (b)
an object
moving in a
certain direction with an acceleration in the perpendicular direction.
3.
An athlete completes one round of a circular track of diameter 200 m in 40 s. What will be
the distance covered
and the displacement
at the
end
of 2 minutes and 20
seconds?
4. .
The velocity of a body
in motion is recorded every
second
as shown-
|
Calculate the –
(a) Acceleration (b) distance travelled
and draw the graph.
6.
Which law of motion gives the measure
of force?
7.
Define 1 newton
force.
8.
Name the principle on which a rocket works.
9.
State Newton’s third law of motion and how does it explain the walking of man on the
ground?
10.
When small boy is trying to push a heavy stone, mention various forces acting
on the
stone.
11.
A 8000 kg engine pulls a train of 5 wagons,
each of 2000 kg, along a horizontal track. If the engine exerts a force of
40000 N and the track offers a friction force of 5000 N, then calculate:
(a)
the net accelerating force;
(b)
the acceleration of the train;
and
(c) the force of wagon 1 on wagon 2.
12.
Derive the second equation of motion S
ut 1 at2 graphically?
13.
Why does a person while firing a bullet
holds the gun tightly
to his shoulders?
14.
Two objects, each of mass 1.5 kg, are moving in the same straight line but in opposite directions. The velocity of each object
is 2.5 m s-1 before the collision
during which they stick
together. What will be the
velocity
of the combined object after
collision?
15.
Derive the third equation of motion- v2-u2=2aS
16.
Why does an
athlete puts some sands or cushion on the
ground while high jumping?
17.
State Newton’s second law of motion
and derive it
mathematically?
18.
Gravitational force acts on all objects in
proportion to their masses. Why then, a heavy object does not fall faster than a
light object?
19.
Differentiate
between mass and weight?
20.
The radius of earth is 6370Km and of mars is
3400 Km. If an object weighs 200N or
earth, what will be its weight
on mars. The mass of mars is 0.11 that of earth.
21.
Derive expression for force of attraction
between two bodies and then define
gravitational constant.
22.
What is the
magnitude of the
gravitational force between the earth and a 1 kg object on its surface?
(Mass of the earth is 6 1024 kg and radius
of the
earth is 6.4 106 .)
23.
How does the weight of an object vary with respect
to mass and radius of the earth? In a
hypothetical case, if the diameter of the earth becomes half of its present value and its mass
becomes four times of its present value, then how would the weight of any object on the
surface of
the
earth be affected?
24.
Show that the
weight of an object on
the moon is 6thof its weight
on the earth..
25.
A ball is gently dropped from a height of 20 m. If its velocity increases uniformly at the rate
of 10 m s-2, with what velocity will it strike the ground? After what time will it strike the
ground?
26.
A ball is thrown vertically upwards with a velocity of 49 m/s. Calculate the maximum
height to
which it rises.
27.
On the earth, a stone is thrown from a height in a direction parallel to the earth’s surface
while another stone is simultaneously dropped from the same height. Which stone would
reach the ground first and why?
28.
State the
factors
on
which acceleration due to gravity (g) depends?
29.
Define electrostatic force.
30.
Calculate the force of gravitation between the earth and the Sun, given that the mass of the
earth = 6 1024 kg and of the Sun = 2 1030 kg. The average distance between the two is
1.5 1011m.
31.
Why do you fall in the forward direction when a moving bus brakes to a stop and fall
backwards when it accelerates from rest?
32.
Prove that if a body is thrown vertically upward, the time of ascent is equal to the time of
descent.
33.
A ball thrown up vertically returns
to the thrower after
6 s. Find
(a) the velocity with which it was thrown up.
(b) the maximum height it reaches, and
(c) its position after 4s.
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