PHYSICS-Work and Energy (SMART INSTITUTE)

01-At what angle, work done will be minimum

02-If 10 kg mass is dropped from a certain height, hits the ground with speed 10 ms-1. The height will be:

03-A body is dropped from 1000 m height, if its potential energy is 8 x 10^8 J. What will be its velocity on reaching the ground?

04-At what angle the work done will be half of its maximum value:

05-A 500 N force is applied on an object and it moves with velocity 10 ms-1. If value of power is 2500 W. Then what will be the angle between force and displacement?

06-The unit of work is:

07-WOF quantity can be calculated by multiplying force and velocity?

08-A body is falling from a height h. After it has fallen a height h/2, it will possess

09-The work done by a force keeping an object in circular motion with constant speed is

10-The energy stored in the dam is:

11-The flying bird has

12-What will be the ratio of kinetic energies of alpha particle and proton if their linear momentum will be same:

13-One erg is equal to;

14-A man pushes a wall with 50 N and it displaces it zero m, his work is:

15-If a mass of 5 kg is lifted upto 5 m height, what will be the work done against the gravitational field?

16-The bodies of 1 kg and 4 kg have same K.E. The ratio in their momentum will be

17-A person stands, holding an object of mass 2 kg at a height of 5m, the work done is

18-A person walks 2m with an acceleration of 5 ms-2, holding an object of mass 2 kg. The work done on the object is?

19-The work done on an object does not depend upon the

20-In free falling system, if potential energy is equal to kinetic energy. Then force of friction of air will

21-The velocity and momentum of a moving body are 10,000 cms-1 and 10,000gcms-1 respectively. The K.E will be

22-If momentum of a moving object is doubled then its K.E will be:

23-Energy stored in the spring of watch is:

24-The momentum and kinetic energy of a ball is numerically equal. The numerical value of velocity is:

25-A force of 3i^+2j^+4k^ N gives displacement of 10 j^ m. The work done is

26-A body travels displacement of 10 m by force of 5N. If work done is 25 J then angle between F and d is

27-Kinetic energy of a body moving with speed of 10 ms-1 is 30J. If its speed becomes 30 m/s its K.E will be:

28-The time taken by an engine of power 10 kW to lift a mass of 200 kg to the height of 40 m is

29-A force "F1" acts on a body through distance "S1"in the direction of motion and does work "W1" , similarly another force "F2" acts on the same body through distance "S2' but in opposite to the direction of motion and does work "W2".Now if F1=F2 and S1=S2 then which statement is correct

30-To travel at a constant speed, a car engine provides 24 kW of useful power. The driving force on the car is 600 N. At what speed does it travel?

31-A force of 1000 N is needed to lift the hook of a crane at a steady velocity. The crane is then used to lift a load of mass 1000 kg at a velocity of 0.50 ms-1. How much of the power developed by the motor of the crane is used in lifting the hook and the load? (Take g as 10 ms-2)

32-Car X is traveling at half the speed of car Y. Car X has twice mass of car Y. Which statement is correct?

33-The amount of work required to stop a moving object is equal to:

34-The power output of a lamp is 6W. How much energy does the lamp give out in 2 minutes?

35-A ball is thrown vertically upwards. Neglecting air resistance, which statement is correct?

36-A man weighing 500 N carries a load of 10 kg to the top of a building in 4 minutes. The work done by the man is 6 x 10^4 J. If he carries the same load in 8 minutes, the work done by the man will be:

37-A person holds a bucket of weight 60 N. He walks 7 m along the horizontal path and then climbs up a vertical distance of 5 m. The work done by the man is:

38-A man M1 of mass 80 kg runs up a staircase in 15 s. Another man M2 also of mass 80 kg runs up the same staircase in 20 s. The ratio of the power developed by them will be:

39-An engine pumps up 100 kg of water through a height of 10 m in 5 s. Given that the efficiency of the engine is 60% , what is the power of the engine? (Take g=10 ms-2)

40-An engine pumps out 40 kg of water in one second. The water comes out vertically upwards with a velocity of 3 ms-1. What is the power of the engine in kiolowatt?

41-A ball of mass 2 kg and another mass 4 kg are dropped together from a 60 feet tall building. After a fall of 30 feet each towards earth, their respective kinetic energies will be in the ratio of:

43-An elevator's motor produces 3000 W power. The speed with which it can lift a 1000 kg load is:

44-In the presence of air friction, the relation for free falling body is:

46-A bomb of mass 30 kg at rest explodes into two pieces of masses 18 kg and 12 kg,. The velocity of 18 kg mass is 6 m/s. The K.E of other mass is:

47-The power needed to lift a mass of 5000 g to height of 1m in 2 s is:

48-3 J of work is done in 3 s, then power is:

49-A stone is thrown up from the surface of earth when it reaches at maximum height. Its total energy is equal to:

50-You lift a suit case from the floor and keep it on a table. The work done by you on the suitcase does not depend on:

51-Slope of work time graph is equal to:

52-K.E of an object of 2 kg having velocity (cos@i^ + sin@j^) ms-1 will be

53-Light and heavy bodies have equal K.E. Which one has the greater momentum?

54-The two bodies with masses m1 and m2 have equal K.Es. If P1 and P2 are their respective momenta, then the ratio between P1 and P2 is:

55-A force of 6 N act horizontally on a stationary mass of 2 kg for 4 s. The energy in J is:

56-If the velocity of a body becomes half, the kinetic energy of the body will become:

57-In a gravitational field when work done by gravity is negative then

58-WOF work is greater?

59-The time taken by an engine of power 10 kW to lift a mass of 200 kg to a height of 40 m is (g=10 ms-2)

60-The wounded spring of a clock possesses: