Question:
What conclusion do you draw when displacement-time graph of a body is as shown in Fig.?
Answer:
The body is moving with a uniform velocity.
Motion
Q 1.
Derive graphically the equation of motion for position-velocity relation of a body moving with uniform acceleration.
Q 2.
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 3.
A particle moves over three quarters of a circle of radius r.What is the magnitude of its displacement ?
Q 4.
When will you say a body is in (i) uniform acceleration? (ii) nonuniform acceleration?
Q 5.
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 6.
Write the three equations of uniformly accelerated motion. Give the meaning of each symbol in them.
Q 7.
Why is a slight blow on a cork of bottle fully filled with a liquid sufficient to break the bottle ?
Q 8.
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 9.
What is represented by the graphs in Fig.?
.
Q 10.
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 11.
What will be the initial velocity of an object under free fall?
Q 12.
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 13.
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 14.
What is pressure in case of fluids ? What is Pascal’s law ?
Q 15.
Under what conditions(s) is the magnitude of average
Q 16.
Name the quantity that represents rate of change of velocity ?
Q 17.
A body starts from rest.What is zero ?
Q 18.
What conclusion do you draw when displacement-time graph of a body is as shown in Fig.?
Q 19.
State velocity-time relation in uniformly accelerated motion. Use graphical method to obtain this relation.
Q 20.
Define buoyant force.What is its unit ?
Q 21.
Draw speed-time graph for a body (i) at rest (ii) in uniform motion (iii) in uniformly accelerated motion.Discuss the results briefly.
Q 22.
The mass of a block made of certain material is 13 5 kg and its volume is
float or sink in water ? Give a reason for your answer.
Q 23.
The density of turpentine oil is
.What will be its relative density ?
Q 24.
What is meant by scalars and vectors?
Q 25.
A body travels a distance of 15 m from A to B and then moves a distance of 20 m at right angles to AB.Calculate the total distance travelled and the displacement.
Q 26.
What can you say about the motion of an object whose distance-time graph is a straight line parallel to the time axis ?
Q 27.
Use graphical method to derive the relation
-
= 2 as,where the symbols have their usual meanings.
Q 28.
A hydraulic automobile lift is designed to lift cars with a maximum mass of 3000 kg.The area of the piston carrying the load is
.What maximum pressure would the smaller piston have to bear ?
Q 29.
Relative density of silver is 10.8.The density of water is
.What is the density of silver in SI units ?
Q 30.
Calculate the pressure when a force of 200 N acts on an
Q 31.
What force acting on an area of
will produce a pressure of 500 Pa ?
Q 32.
What is the relationship between the buoyant force on an object and the liquid displaced by it ?
Q 33.
Why is it easier to swim in sea water than in river water ?
Q 34.
Discuss three important practical aspects of pressure related to daily life.
Q 35.
State Archimedes’ Principle ? What is the relation between true weight,apparent weight and the buoyant force ?
Q 36.
What is the relation between true weight,apparent weight and the loss in weight of a body immersed in a fluid ? Give some practical applications of Archimedes’Principle.
Q 37.
Why does a person feel pain when he stands on a pile of gravel than when he stands on a bed of sand ?
Q 38.
Why are sleepers used below the rails ?
Q 39.
Human corpse always floats on the surface of water,but the head always stays within water.Why ?
Q 40.
When a plastic block is released under water,it never stays under water but instead comes to the surface of water.Explain why ?
Q 41.
Pascal’s law states that a fluid in a confined space expands into every possible space if it is put under pressure.This law plays a very important role in our lives.Give three applications with brief description.
Q 42.
A particle moves along the x axis from A to B. Which Of the following values of the initial and final coordinates, which results in a negative displacement?
(a) A = 4m, B = 6m
(b) A = −4m, B = −2m
(c) A = −4m, B = −8m
(d) A = −4m, B = 2m
Q 43.
A bus decreases its speed from 80 km/h to 60 km/h in 5 s. Find the acceleration of the bus.
Q 44.
A racing car has a uniform acceleration of 4 m s–2.
What distance will it cover in 10 s after start?
Q 45.
What does the slope of distance-time graph indicate?
Q 46.
A body thrown vertically upwards reaches a maximum height h.It then returns to ground.Calculate the distance travelled and the displacement.
Q 47.
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 48.
The following is the distancc-time table of a moving car.
(a) Use a graph paper to plot the distance travelled by the car versus the time.
(b) When was the car travelling at the greatest speed ?
(c) What is the average speed of the car ?
(d) What is the speed between 11.25 am and 11-40 am ?
(e) During a part of the journey, the car was forced to slow down to 12 km/h.At what distance did this
| Time | Distance |
|---|
10.05 am
10.25 am
10.40 am
10.50 am
11.00 am
11.10 am
11.25 am
11.40 am | 0 km
5 km
12km
22 km
26 km
28 km
38 km
42 km |
Q 49.
A scooter acquires a velocity of 36 km/h in 10 seconds just after the start.Calculate the acceleration of the scooter.
Q 50.
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.
