Question:
What does the path of an object look like when it is in uniform motion?
Answer:
: When an object is in uniform motion, it means its speed is constant. Or it travels equal distance in equal intervals of time. The path may be a straight line or curved or zig-zag. Its direction may also vary but the magnitude is fixed.
Motion
Q 1.
Derive graphically the equation of motion for position-velocity relation of a body moving with uniform acceleration.
Q 2.
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 3.
What can you calculate from speed-time graph of a body ?
Q 4.
Why is it easier to swim in sea water than in river water ?
Q 5.
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 6.
What is represented by the graphs in Fig.?
.
Q 7.
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 8.
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 9.
When will you say a body is in (i) uniform acceleration? (ii) nonuniform acceleration?
Q 10.
Why does a person feel pain when he stands on a pile of gravel than when he stands on a bed of sand ?
Q 11.
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 12.
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 13.
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 14.
Under what conditions(s) is the magnitude of average
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.
Distinguish between speed and velocity.
Q 17.
In addition to speed,what else should be known to predict the position of a moving body from a given starting point ?
Q 18.
What do the graphs shown in Fig.indicate?
Q 19.
The density of turpentine oil is
.What will be its relative density ?
Q 20.
Are motion and rest absolute or relative? Explain with an example.
Q 21.
What does the path of an object look like when it is in uniform motion?
Q 22.
Discuss three important practical aspects of pressure related to daily life.
Q 23.
Why are sleepers used below the rails ?
Q 24.
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 25.
What does the slope of distance-time graph indicate?
Q 26.
Can distance be negative ?
Q 27.
What remains constant in uniform circular motion ?
Q 28.
A particle moves over three quarters of a circle of radius r.What is the magnitude of its displacement ?
Q 29.
If velocity-time graph of a body is as shown in Fig.,what is the nature of motion ?
Q 30.
Use graphical method to derive the relation
-
= 2 as,where the symbols have their usual meanings.
Q 31.
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 32.
Calculate the mass of a body whose volume is
and relative density is 0.52.
Q 33.
Explain the reason due to which buoyancy arises.
Q 34.
An electric train is moving with a velocity of 120 km/h. How much distance will it move in 30 s ?
Q 35.
When will you say a body is in (») uniform acceleration ? (ii) non-uniform acceleration ?
Q 36.
What is the SI unit of acceleration ?
Q 37.
A body starts from rest.What is zero ?
Q 38.
What conclusion do you draw when displacement-time graph of a body is as shown in Fig.?
Q 39.
Explain what is meant by uniform circular motion.Give at least three examples.
Q 40.
The mass of a density bottle is 25 g when empty, 50 g when filled completely with water and 365 g when filled completely with mercury. Find the density of mercury.
Q 41.
A bottle can hold 100 g of water at 4°C.What mass of sea water (density =
) can it hold ?
Q 42.
A body of 2.0 kg floats in a liquid.What is the buoyant force on the body ?
Q 43.
State one important effect produced by the buoyant force exerted by water.
Q 44.
When a plastic block is released under water,it never stays under water but instead comes to the surface of water.Explain why ?
Q 45.
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 46.
(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 47.
An object has moved through a distance. Can it have zero displacement? If yes, support your answer with an example.
Q 48.
A train starting from a railway station and moving with uniform acceleration attains a speed 40 km/h in 10 minutes. Find its acceleration.
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?
