Question:
Ahmed is moving in his car with a velocity of 45 km/h.How much distance will he cover (a) in one minute and (b) in one second ?
Motion
Q 1.
Derive graphically the equation of motion for position-velocity relation of a body moving with uniform acceleration.
Q 2.
What can you calculate from speed-time graph of a body ?
Q 3.
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 4.
Why is it easier to swim in sea water than in river water ?
Q 5.
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 6.
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 7.
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 8.
When will you say a body is in (i) uniform acceleration? (ii) nonuniform acceleration?
Q 9.
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 10.
A train 100 m long moving on a straight level track passes a pole in 5 s. Find (a) the speed of the train (b) the time it will take to cross a bridge 500 m long.
Q 11.
What is represented by the graphs in Fig.?
.
Q 12.
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 13.
Under what conditions(s) is the magnitude of average
Q 14.
In addition to speed,what else should be known to predict the position of a moving body from a given starting point ?
Q 15.
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 16.
Why does a person feel pain when he stands on a pile of gravel than when he stands on a bed of sand ?
Q 17.
Distinguish between speed and velocity.
Q 18.
What does the path of an object look like when it is in uniform motion?
Q 19.
What does the slope of distance-time graph indicate?
Q 20.
What do the graphs shown in Fig.indicate?
Q 21.
The density of turpentine oil is
.What will be its relative density ?
Q 22.
Are motion and rest absolute or relative? Explain with an example.
Q 23.
What remains constant in uniform circular motion ?
Q 24.
Use graphical method to derive the relation
-
= 2 as,where the symbols have their usual meanings.
Q 25.
Discuss three important practical aspects of pressure related to daily life.
Q 26.
A train is running at a speed of 72 km/h. It crosses a bridge of length half kilometer in 1 minute. Calculate the length of the train.
Q 27.
If velocity-time graph of a body is as shown in Fig.,what is the nature of motion ?
Q 28.
Explain what is meant by uniform circular motion.Give at least three examples.
Q 29.
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 30.
Why are sleepers used below the rails ?
Q 31.
(a)
Which human virtue was at stake when Archimedes came out with his principle while bathing in a tub ?
(b) Briefly discuss three cases where Archimedes Principle is at work.
Q 32.
An electric train is moving with a velocity of 120 km/h. How much distance will it move in 30 s ?
Q 33.
A motor cycle moving with a speed of 5 m/s is subjected to an acceleration of 0.2
.Calculate the speed of the motor cycle after 10 second,and the distance travelled in this time.
Q 34.
When will you say a body is in (») uniform acceleration ? (ii) non-uniform acceleration ?
Q 35.
What can you say about the motion of an object whose distance-time graph is a straight line parallel to the time axis ?
Q 36.
Can distance be negative ?
Q 37.
A particle moves over three quarters of a circle of radius r.What is the magnitude of its displacement ?
Q 38.
State velocity-time relation in uniformly accelerated motion. Use graphical method to obtain this relation.
Q 39.
Calculate the mass of a body whose volume is
and relative density is 0.52.
Q 40.
A bottle can hold 100 g of water at 4°C.What mass of sea water (density =
) can it hold ?
Q 41.
A solid of density 5000
weighs 0.5 kg f in air.It is completely immersed in water of density 1000
.
(a) Calculate the apparent weight of the solid in water.
(b) What will be its apparent weight if water is replaced by a liquid of density 8000
?
Q 42.
State one important effect produced by the buoyant force exerted by water.
Q 43.
Why is a slight blow on a cork of bottle fully filled with a liquid sufficient to break the bottle ?
Q 44.
Explain the reason due to which buoyancy arises.
Q 45.
When a plastic block is released under water,it never stays under water but instead comes to the surface of water.Explain why ?
Q 46.
Breathing is the process that moves air in (inhaling) and out (exhaling) of the lungs.Breath is life as breathing provides 99% of energy to our bodies.
(a) What happens when we inhale ?
(b)Why a person with pulmonary disease has difficulty in breathing ?What message does it convey ?
(c) What is done to make a newborn have his first breath ?
Q 47.
An object has moved through a distance. Can it have zero displacement? If yes, support your answer with an example.
Q 48.
Under what condition(s) is the magnitude of average velocity of an object equal to its average speed?
Q 49.
A bus starting from rest moves with a uniform acceleration of 0.1 ms–2 for 2 minutes.
Find (a) the speed acquired, (b) the distance travelled.
Q 50.
The speed-time graph for a car is shown is figure below.
(a) Find how far does the car travel in the first 4 seconds. Shade the area on the graph that represents the distance travelled by the car during the period.
(b) Which part of the graph represents uniform motion of the car?
