work, energy power iit questions

Welcome, To STUDYEVERTHING
Today, we are going to cover the MOST IMPORTANT QUESTION from PHYSICS chapter KINAMATICS for exams like CBSE board, NEET, JEE MAIN & JEE ADVANCE.
First try to solve the question on your own in the allotted time (45 minutes). Then check the answers.
If you want to know the answers in detail you can simply download the pdf file which is at the end of the session.
So, what are you waiting for,
Let's crack it.

You may choose the language using translater, located at top of the right-hand side, as Hindi, Gujarati, etc.

STUDY EVERTHING

TIMER:

45min

1. A ball of 50g is dropped vertically downwards from the top of a 5m high tower. If the ball hits ground and bounces back without any loss of energy, then the impulse of force exerted on the ground in one second will be
a.0.5 Ns
b.5×10^-2 Ns
c.10 Ns
d.1 Ns

2. If the Average kinetic, potential and total energies of simple pendulum are E_K, E_P and E_T respectively, then
a.E_K= 1/2E_P, E_T= 2E_K
b.E_K= E_P= 1/2E_T
c.E_P= 1/2E_K, E_T= 2E_P
d.E_K= E_P= E_T

3. A 80kg man runs up a staircase of 4m in 8s. If the value of acceleration due to gravity is 10m /s², his average power output is
a.400 W
b.800 W
c.1600 W
d.3200 W

4. A particle us moving freely. Then its
a.kinetic energy is always greater than zero
b.potential energy is greater than zero and kinetic energy is less than zero
c.potential energy is less than zero and kinetic energy is greater than zero
d.potential energyis zero and kinetic energyis less than zero

5. Two masses of 1gm and 4gm are moving of equal kinetic energies. The ratio of their magnitude of their linear momentum is
a.4:1
b.1:
c.1:2
d.1:16

6. A spring of force-constant k is cut into two pieces such that one piece is double the length of other. Then the long piece will have force constant of
a.(2/3)k
b.(3/2)k
c.3k
d.6k

7. A wind-powered generator converts wind energy into electrical energy. Assume that generator converts fixed fraction of wind energy intercepted by its blades into electrical energy. For the wind speed v, the electrical power output will be proportional to
a.v
b.v²
c.v³
d. v⁴

8. A block of mass m moving on the frictionless horizontal surface collide with a spring of spring constant k and compress it by length L. The maximum momentum of the block after the collision is

a. kL²/2M
b.√(ML).K
c. ML²/k
d.zero

9. A block of 2kg mass slides on horizontal floor with the speed of 4m/s. It strikes on uncompressed, and compresses it till the block is motionless. The kinetic frictional force is 15N and spring constant is 10,000N/m. The spring compresses by
a.8.5cm
b.5.5cm
c.2.5cm
d.11cm

10. A block of mass 0.5kg is moving with a speed of 2m/s on a smooth surface. It strikes another mass 1kg and then they move together as a single body energy loss during the collision is
a.0.16J
b.1J
c.0.67J
d.0.34J

NUMERICAL TYPE

1. The power output of a machine that lifts a 600kg weight through a height of 20m in 1minute is (in W)

2. Two small particle of equal masses start moving in opposite direction from point A in horizontal circular orbit. Their tangential velocities are v and 2v, respectively, as shown in the figure. Between Collision the particles moves with constant speed. After making how many elastic collision, other then that at A, these two particles again reach at point A?

3. A block of mass 2kg is free to maven along x-axis. It is at rest from t=0 onwards it is subject to time-dependent the force F(t) in x direction. The force F(t) varies with t as shown in figure. The kinetic energy of the block after 4.5 seconds is

4. A spring of spring of spring constant 5×10³N/m is stretched initially by 5cm from the unstretched position. The work required to stretched it further by another 5cm is (N-m)

5. A person try to lose weight by burning fat lifts mass of 10kg Upton a height of 1m 1000 times assume that the potential energy he lose each time he lower the mass is dissipated. How much fat will he use up considering the work done only when the weight is lifted up? The fat supplies 3×10⁷ of energy per kg which is converted to mechnical energy with a 20% efficiency rate. Take g=10m/s².( in kg)

JEE ADVANCE

1. A piece of wire bent in form of a parabola y=kx² (y-axis vertical) with a head of mass m on it. The bead can slides on wire without friction. It stays at lowest point of parabola when the wire is at rest. Now the wire is accelerated parallel to x-axis with a constant acceleration a. The distance of new equilibrium point of the bead where the bead can stay at rest with respect to wire, from the y-axis is
a.a/gk
b.a/2gk
c.2a/gk
d.a/4gk

2. A stone tied to string of length L is whirled in vertical circle with the another end of string at the centre. At the certain instant of time, the stone is at its lowest position and has a speed u. The magnitude of change of velocity as it reaches a position where the string is horizontal is
a.(u²-2gL)^1/2
b.(2gL)^1/2
c.(u²-gL)^1/2
d. (2(u²-gL))^1/2

3. A 0.5kg block slides from point A (as shown in figure) on horizontal track with the initial speed of 3m/s toward a weightless spring of length 1m and spring constant 2N/m. The part AB of the track is frictionless and the part BC has coefficient of static and kinetic friction as 0.22 and 0.2 respectively. If the distances AB and BC are 2m and 2.14 m respectively, find the total distance through which block moves before it comes to rest completely. Take g= 10m/s².

a.4.24
b.2.42
c.6
d.4

4. A particle of mass 0.2kg moving in one direction under a force that delivers a constant power 0.5 W to the particle. If the initial speed(in m/s) of the particle is zero, the speed(in m/s) after 5seconds is
a.5
b.4
c.3
d.1

5. Consider an elliptical shaped rail in vertical plane with OP=3m and OQ=4m. A block of mass 1kg is pulled along a rail from PTO Q with a force of 18N, which is always parallel to line PQ(see figure). Assuming that frictionless loses, the kinetic energy of block when it reaches Q is (n×10)joules. The value of n is ,(Take g= 10m/s²).

a.6
b.5
c.7
d.9

Download the detailed answer pdf of the most important questions from Chapter WORK, ENERGY AND POWER HERE.

Unit and measurements most important questions	click here
Kinamatic most important questions	click here
Law of motion most important questions	click here
Work, energy and power most important questions	click here
Nit cutoff	click here
Iiit cutoff	click here

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work, energy power iit questions