Question:
What does the slope of distance-time graph indicate?
Answer:
Slope indicates the speed of the object.
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.
(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 15.
What does the slope of distance-time graph indicate?
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
.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+
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 =
.
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
-
= 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.
Fill in the blanks :
If the position of an object does not change with time, it is said to be at _____.
Q 33.
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 34.
A body is moving uniformly with a velocity of 5 m/s. Find graphically the distance travelled by it in 5 s.
Q 35.
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 36.
What can you calculate from speed-time graph of a body ?
Q 37.
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 38.
Calculate the pressure when a force of 200 N acts on an
Q 39.
What force acting on an area of
will produce a pressure of 500 Pa ?
Q 40.
Define buoyant force.What is its unit ?
Q 41.
Discuss three important practical aspects of pressure related to daily life.
Q 42.
What do you mean by the terms density and relative density ?How are these terms related to each other ?
Q 43.
Explain the reason due to which buoyancy arises.
Q 44.
Why do objects float or sink when placed on the surface of a liquid ?
Q 45.
What is Archimedes’ Principle ? How can it be experimentally verified ?
Q 46.
State Archimedes’ Principle ? What is the relation between true weight,apparent weight and the buoyant force ?
Q 47.
When a plastic block is released under water,it never stays under water but instead comes to the surface of water.Explain why ?
Q 48.
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 49.
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 50.
Distinguish between speed and velocity.