Question:
In the above question,calculate
(i) distance travelled from O to A.
(ii) distance travelled from B to C.
(iii) total distance travelled by the body in 16 sec.
Answer:
(i) 12 m ; (ii)18 m ;(iii) 66 m
Motion
Q 1.
Derive graphically the equation of motion for position-velocity relation of a body moving with uniform acceleration.
Q 2.
Puja and Neha are close friends.Puja is a science graduate and Neha is a commerce graduate.Puja finds that while driving on a clear highway,Neha often exceeds the speed limit and agrues that there is no harm in doing so when the road is clear.Puja does not agree with her and tells her that with increase in speed, stopping distance of car would increase and she would not be able to manage things if some stray cattle etc. appears suddenly on the way.Read the above passage and answer the following questions :
(i) Is Puja right in her statement?
(ii) What values are displayed by Puja in her statement?
(iii) How is stopping distance related to speed of vehicle?
Q 3.
The density of turpentine oil is
.What will be its relative density ?
Q 4.
Are motion and rest absolute or relative? Explain with an example.
Q 5.
A cyclist cycles for t second at a speed of 3 m/s and then for the same time at a speed of 5 m/s along a straight road due north. What is the average speed of the cyclist?
Q 6.
Mathematically prove that the distance (S) travelled by an object is the average mean of initial velocity(u) and final velocity(v) having constant acceleration(a) in the direction of motion in a straight line.
Q 7.
A force of 16 N is distributed uniformly on one surface of a cube of edge 8 cm.Find the pressure on this surface.
Q 8.
Calculate the greatest and the least pressure exerted by a metal block of size 20 cm x 8 cm x 5 cm and having a mass of 5 kg.
Q 9.
Air is a fluid and our bodies displace air.As a result of this,a buoyant force is acting on each one of us.
(a)What is the approximate density of your body ?
(b) What is your approximate volume ?
(c) Estimate the magnitude of the buoyant force on you due to the air displaced.Consider your mass to be 75 kg.
(d)Does it mean that your weight is more than the scale reading ?
(Given density of air,pa =
)
Q 10.
Distinguish between speed and velocity.
Q 11.
A particle is moving in a circle of diameter 5 m. Calculate the distance covered and the displacement when it completes 3 revolutions.
Q 12.
If velocity-time graph of a body is as shown in Fig.,what is the nature of motion ?
Q 13.
What is represented by the graphs in Fig.?
.
Q 14.
The mass of a solid rectangular block of iron is 23.6 g and its dimensions are 2.1 cm x 1.2 cm x 1.1 cm.Calculate the density of iron.
Q 15.
Define thrust What is its unit ?
Q 16.
An object weighs 9.8 N in air and 9.0 N when fully immersed in water.How much is the buoyant force on the object ?
Q 17.
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?
Q 18.
When will you say a body is in (i) uniform acceleration? (ii) nonuniform acceleration?
Q 19.
Fill in the blanks :
If the position of an object does not change with time, it is said to be at _____.
Q 20.
Use graphical method to derive the relation
-
= 2 as,where the symbols have their usual meanings.
Q 21.
Draw distance-time graph for a body (i) at rest (ii) in uniform motion (iii) in non-uniform motion.Discuss their interpretation.
Q 22.
A cube of edge length 10 cm is placed inside a liquid.The pressure at the centre of the face is 15 Pa.Find the force exerted by the liquid on this face.
Q 23.
Why is a slight blow on a cork of bottle fully filled with a liquid sufficient to break the bottle ?
Q 24.
A train is travelling at a speed of 90 kmh–1. Brakes are applied so as to produce a uniform acceleration of – 0.5 ms–2. Find how far the train will go before it is brought to rest.
Q 25.
Fill in the blanks :
The rate of change of velocity of a moving body with time is called ______.
Q 26.
A train starting from rest moves with a uniform acceleration of 0.2
for 5 minutes.Calcualte the speed acquired and the distance travelled in this time.
Q 27.
Can distance be negative ?
Q 28.
What remains constant in uniform circular motion ?
Q 29.
What can you calculate from speed-time graph of a body ?
Q 30.
State velocity-time relation in uniformly accelerated motion. Use graphical method to obtain this relation.
Q 31.
The mass of an empty 40 litre petrol tank of a vehicle is 8.0 kg.What will be its mass when filled completely with a fuel of density 700
Q 32.
A metallic sphere of radius 2.0 cm is completely dipped in water.Find the force of buoyancy on it.
Q 33.
Why does a person feel pain when he stands on a pile of gravel than when he stands on a bed of sand ?
Q 34.
A body thrown vertically upwards reaches a maximum height h.It then returns to ground.Calculate the distance travelled and the displacement.
Q 35.
Under what conditions(s) is the magnitude of average
Q 36.
A racing car has a uniform acceleration of 4
.What distance will it cover in 10 s after start ?
Q 37.
Name the terms represented by various symbols in the equation, v = u + at.
Q 38.
Why is it easier to swim in sea water than in river water ?
Q 39.
What does the odometer of an automobile measure?
Q 40.
What does the path of an object look like when it is in uniform motion?
Q 41.
What does the slope of distance-time graph indicate?
Q 42.
Fig (below) shows the distance-time graph of three objects A,B and C. Study the graph and answer the following questions:
(a) Which of the three is travelling the fastest?
(b) Are all three ever at the same point on the road?
(c) How far has C travelled when B passes A?
(d) How far has B travelled by the time it passes C?
Q 43.
A train travels some distance with a speed of 30 km/h and returns with a speed of 45 km/h.Calculate the average speed of the train.
Q 44.
A ship is moving at a speed of 56 km/h.One second later,it is moving at 58 km/h.What is its acceleration ?
Q 45.
Distinguish between speed and velocity.
Q 46.
When will you say a body is in (») uniform acceleration ? (ii) non-uniform acceleration ?
Q 47.
A trolley, while going down an inclined plane, has an acceleration of
starting from rest.What will be its velocity 3 s after the start ?
Q 48.
The displacement of a moving object in a given interval of time is zero.Would the distance travelled by the object also be zero ?Justify your answer.
Q 49.
Can displacement and distance ever be equal ?
Q 50.
What is SI unit of speed ? Is it same for velocity ?
