MOTION - Welcome to NRT INDIA

Transcription

MOTION - Welcome to NRT INDIA
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NRT INDIA
MOTION
MOTION
VERY SHORT ANSWER TYPE QUESTIONS
1. Have you ever experienced that the train in
which you are sitting appears to move while it is
at rest?
14. Two car A and B have their x ―t graphs as
given: which one has the grater velocity ?
x
A
2. An object has moved through a distance. Can it
have zero displacement? If yes, support your
answer with an example.
3. A farmer moves along the boundary of a square
field of side 10 m in 40 s. What will be the
magnitude of displacement of the farmer at the
end of 2 minutes 20 seconds?
4. Which of the following is true for displacement?
B
30°
t
15. What type of motion is associated with a
pendulum ?
(a)It can not be zero
16. Give one type of motion where distance and
displacement are same.
(b)its magnitude is greater than the distance
travelled by the object
17. When a moving car returns to the same point
what will be the displacement.
5. An object travels 16 m in 4 s and then another
16 m in 2 s. What is the average speed of the
object?
6. Under what condition(s) is the magnitude of
average velocity of an object equal to its average
speed?
7. What does the odometer of an automobile
measure?
18. Express km/ h2 in m / s −2 .
19. What does v stand for in v = u + at ?
20. Draw the velocity-time graph for a body moving
with a uniform acceleration. Assume that the
body is initially at rest.
21. Out of the following, identify the graph which
corresponds to a motion with
(i) Uniform retardation
(ii) Zero acceleration.
10. What is the quantity of which is measured by the
area occupied below the velocity time graph ?
Speed
9. What can you say about the motion of an whose
distance-time graph is a straight line parallel to
the time axis?
Speed
8. What is the nature of distance – time graph for
uniform and non-uniform motion of an object?
Time
Time
A
B
12. What is instantaneous velocity ?
13. If 5 m/s and 10 m/s are the velocities of a body
having a uniform acceleration in some times
interval, what will be its average velocity ?
Speed
11. Relate 36 km/h with m/sec.
Time
C
NRT India , 14/32, RLB Road Near Munshi Pulia, Indira Nagar, Lucknow. Call: 0522-2714802, 9415905513, 8090510938
Branches : Indira Nagar, Gomti Nagar, Hazratganj
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NRT INDIA
MOTION
SHORT ANSWER TYPE QUESTIONS
1.
Distinguish between speed and velocity .
2.
Usha swims in a 90 m long pool. She covers
180 m in one minute by swimming from one end
to the other and back along the same straight
path. Find the average speed and average
velocity of Usha.
3.
4.
5.
Starting from a stationary position, Rahul
paddles his bicycles to attain a velocity of 6 m/s
in 30 s. Then the applies brakes such that the
velocity of the bicycle comes down to 4 m/s in
the next 5 s. Calculate the acceleration of the
bicycle in both the cases.
A train starting from rest attains a velocity of 72
km/h in 5 minutes. Assuming that the
acceleration is uniform, find (i) the acceleration
nd (ii) the distance travelled by the train for
attaining this velocity.
The brakes applied to a car produce an
acceleration of 6 m/s 2 in the opposite direction
to the motion. If the car takes 2 s to stop after
the application of brakes, calculate the distance
it travels during this time.
6.
Define uniform motion.
7.
What do you mean by average velocity ?
8.
List the importance of v―t graph.
9.
Write two relations connecting x, r, θ, ω and v
where symbols carry usual meaning.
10. Derive the relation v 2 = u2 + 2as . Draw the
shape of v―t graphs in the following cases :
(i)
SHORT ANSWER TYPE QUESTIONS
1.
Joseph jogs from one end A to the other end B
of a straight 300 m road in 2 minutes 50
seconds and the n turns around the jogs 100 m
back to point C in another 1 minute. What are
Joseph’s average speeds and velocities in
jogging (a) from A to B and (b) from A to C?
2.
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?
3.
A car travels 30 km with a speed of 40 km/h and
the next 30 km with a uniform speed of 20 km/h.
Find its average speed.
4.
On a 120 km track, a train travels the first 30 km
at a uniform speed of 30 km/h. How fast should
the train travel over the next 90 km so as to
average 60 km/h for the entire trip?
5.
A train travels at a speed of 60 km/h for 0.52 h,
at 30 km/h for the next 0.24 h and then at 70
km/h for the next 0.71 h. What is the average
speed of the train?
6.
A scooterist travels at a speed of 5 m/s for two
minutes, at 12.5 m/s for 10 minutes and then
with 10 m/s for 5 minutes. What is the average
velocity and distance curved in this time?
7.
A ship is moving at a speed of 56 km/hr. One
second later, it is moving at a speed of 58
km/hr. What is (i) its acceleration, and (ii) the
distance covered ?
8.
A car moves in a circular path of radius 14 m at
a speed of 10 m/s. Evaluate :
(a) Time taken to complete the circle
Uniform retardation
(i) Does the motion have uniform acceleration?
Give reasons.
(ii) non-uniform acceleration
(ii) Find the angular velocity.
11. A car starts from rest and accelerates with 2
m/ s 2 for 10 seconds. After maintaining the
velocity for 10 seconds, it comes to rest
decelerating by 1 m/s 2 . Draw the shape of v―t
graph.
9.
Define acceleration and state its SI unit. For
motion long a straight line, when do we consider
the acceleration to be (i) positive (ii) negative ?
Give an example of a body in uniform
acceleration.
NRT India , 14/32, RLB Road Near Munshi Pulia, Indira Nagar, Lucknow. Call: 0522-2714802, 9415905513, 8090510938
Branches : Indira Nagar, Gomti Nagar, Hazratganj
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NRT INDIA
MOTION
10. Define circular motion. Is circulatory motion an
accelerated motion? Give reasons.
11. What do you understand by the term
acceleration ? When is acceleration positive
and when is negative ? State the units of
acceleration in S. I. system.
LONG ANSWER TYPE QUESTIONS
1. Derive the three basic equations of motion for a
body moving in a straight line with constant
acceleration.
2.
The figure below shows the x―t graph of three
people A, B and C. On the basis of the graph,
answer the following with reasons ;
(i)
Who among the three is travelling the
fastest ?
(ii) Are all three ever at the same point on the
road?
(iii) Where is C at a time when B passes A ?
(iv) How far did B travel between the time he
passed C and A?
B
C
Distance (km)
12
10
A
11
8
6
4
2
x 0
0.4
0.8
1.2
1.6
Time (t)
NRT India , 14/32, RLB Road Near Munshi Pulia, Indira Nagar, Lucknow. Call: 0522-2714802, 9415905513, 8090510938
Branches : Indira Nagar, Gomti Nagar, Hazratganj