Physics

Motion

Question:

Fill in the blanks :
The rate of change of velocity of a moving body with time is called ______.

Answer:

acceleration

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Motion

Q 1.

Fill in the blanks :
The rate of change of velocity of a moving body with time is called ______.

Q 2.

The equation S = ut + ½at2 gives information as
(a) velocity is a function of time.
(b) velocity is a function of position.
(c) Position is a function of time.
(d) Position is function of velocity and time.

Q 3.

Are motion and rest absolute or relative? Explain with an example.

Q 4.

What do you mean by a body in rest?

Q 5.

Under what condition(s) is the magnitude of average velocity of an object equal to its average speed?

Q 6.

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 7.

A bus decreases its speed from 80 km/h to 60 km/h in 5 s. Find the acceleration of the bus.

Q 8.

Which of the following is true for displacement?
(a) It cannot be zero.
(b) Its magnitude is greater than the distance travelled by the object.

Q 9.

A racing car has a uniform acceleration of 4 m s–2.
What distance will it cover in 10 s after start?

Q 10.

What is the average velocity over the “round trip” of an object that is thrown straight up from the ground and falls straight back down to the ground?

Q 11.

Which of the following is true for displacement ?
(a) It cannot be zero.
(b) Its magnitude is greater than the distance travelled by the object.

Q 12.

When will you say a body is in (i) uniform acceleration? (ii) nonuniform acceleration?

Q 13.

Distinguish between speed and velocity.

Q 14.

What does the slope of distance-time graph indicate?

Q 15.

(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 16.

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 425 cm2.What maximum pressure would the smaller piston have to bear ?

Q 17.

What is locomotion ?

Q 18.

Using graphical method,derive the equations
v=u+at and s=ut+12at2
where symbols have their usual meanings.

Q 19.

State velocity-time relation in uniformly accelerated motion. Use graphical method to obtain this relation.

Q 20.

Calculate the mass of air enclosed in a room of length,breadth and height equal to 5 m, 3 m and 4 m respectively.Density of air =1.3 Kg/m3.

Q 21.

In addition to speed,what else should be known to predict the position of a moving body from a given starting point ?

Q 22.

A scalar quantity has ?
(a) magnitude only
(b) direction only
(c) both direction and magnitude
(d) none of these

Q 23.

A body of 2.0 kg floats in a liquid.What is the buoyant force on the body ?

Q 24.

Why do you feel lighter when you swim ?

Q 25.

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.

Q 26.

Derive graphically the equation of motion for position-velocity relation of a body moving with uniform acceleration.

Q 27.

A particle is moving in a circle of diameter 5 m. Calculate the distance covered and the displacement when it completes 3 revolutions.

Q 28.

What is the acceleration of a body moving with uniform velocity ?

Q 29.

Explain the terms : uniform motion and non-uniform motion with examples.

Q 30.

Use graphical method to derive the relation v2-u2= 2 as,where the symbols have their usual meanings.

Q 31.

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 32.

A trolley, while going down an inclined plane, has an acceleration of 2 cm s–2. What will be its velocity 3 s after the start?

Q 33.

Fill in the blanks :
If the position of an object does not change with time, it is said to be at _____.

Q 34.

A body is moving with a velocity of 15 m/s. If the motion is uniform,what will be the velocity after 10 s ?

Q 35.

A body is moving uniformly with a velocity of 5 m/s. Find graphically the distance travelled by it in 5 s.

Q 36.

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 37.

What can you calculate from speed-time graph of a body ?

Q 38.

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 39.

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 40.

Calculate the pressure when a force of 200 N acts on an

Q 41.

What force acting on an area of 0.5 m2 will produce a pressure of 500 Pa ?

Q 42.

Define buoyant force.What is its unit ?

Q 43.

Discuss three important practical aspects of pressure related to daily life.

Q 44.

What do you mean by the terms density and relative density ?How are these terms related to each other ?

Q 45.

Explain the reason due to which buoyancy arises.

Q 46.

Why do objects float or sink when placed on the surface of a liquid ?

Q 47.

What is Archimedes’ Principle ? How can it be experimentally verified ?

Q 48.

State Archimedes’ Principle ? What is the relation between true weight,apparent weight and the buoyant force ?

Q 49.

When a plastic block is released under water,it never stays under water but instead comes to the surface of water.Explain why ?

Q 50.

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.