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Work, Power & Energy

238 Questions Start Errorless Test
All Exams Allen Advance Errorless
IIT-JEE 2006 Q176 Errorless 9. JEE Section MSQ
A ball moves over a fixed track as shown in the figure. From A to B the ball rolls without slipping. Surface BC is frictionless. $K_{A}$ , $K_{B}$ and $K_{C}$ are kinetic energies of the ball at A, B and C, respectively, Then
A.
$h_A > h_C:K_B > K_C$
B.
$h _ {A} > h _ {C}: K _ {C} > K _ {A}$
C.
$h_{A}=h_{C}:K_{B}=K_{C}$
D.
$h_{A}<h_{C}:K_{A}>K_{C}$
Kerala PET 2005 Q177 Errorless 1. Work Done by Constant Force MCQ
A ball is released from the top of a tower. The ratio of work done by force of gravity in first, second and third second of the motion of the ball is
A.
$1:2:3$
B.
$1:4:9$
C.
$1:3:5$
D.
$1:5:3$
AIEEE 2005 Q178 Errorless 3. Conservation of Energy and Momentum MCQ
The block of mass M moving on the frictionless horizontal surface collides with the spring of spring constant K and compresses it by length L. The maximum momentum of the block after collision is
A.
Zero
B.
$\frac{ML^2}{K}$
C.
$\sqrt{MK} L$
D.
$\frac{KL^2}{2M}$
AIEEE 2005; AIIMS 2007 Q179 Errorless 3. Conservation of Energy and Momentum MCQ
A spherical ball of mass 20 kg is stationary at the top of a hill of height 100 m. It slides down a smooth surface to the ground, then climbs up another hill of height 30 m and finally slides down to a horizontal base at a height of 20 m above the ground. The velocity attained by the ball is
A.
10 m/s
B.
$10\sqrt{30}$ m/s
C.
40 m/s
D.
20 m/s
J & K CET 2005; NEET (Karnataka) 2013 Q180 Errorless 4. Power MCQ
A man does a given amount of work in 10 sec. Another man does the same amount of work in 20 sec. The ratio of the output power of first man to the second man is
A.
1
B.
1/2
C.
2/1
D.
None of these
J & K CET 2005 Q181 Errorless 4. Power MCQ
If the heart pushes 1 cc of blood in one second under pressure $20000 \, N/m^{2}$ the power of heart is
A.
0.02 W
B.
400 W
C.
$5 \times 10^{-10} \, W$
D.
0.2 W
BCECE 2004 Q182 Errorless 1. Work Done by Constant Force MCQ
A ball of mass m moves with speed v and strikes a wall having infinite mass and it returns with same speed then the work done by the ball on the wall is
A.
Zero
B.
mv J
C.
m/v.J
D.
v/m J
DCE 2004 Q183 Errorless 1. Work Done by Constant Force MCQ
A man starts walking from a point on the surface of earth (assumed smooth) and reaches diagonally opposite point. What is the work done by him
A.
Zero
B.
Positive
C.
Negative
D.
Nothing can be said
AIEEE 2004 Q184 Errorless 1. Work Done by Constant Force MCQ
A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the particle, the motion of the particle takes place in a plane. It follows that
A.
Its velocity is constant
B.
Its acceleration is constant
C.
Its kinetic energy is constant
D.
It moves in a straight line
AIEEE 2004 Q185 Errorless 2. Work Done by Variable Force MCQ
A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement $x$ is proportional to
A.
$x^2$
B.
$e^x$
C.
$x$
D.
$\log_e x$
UPSEAT 2004 Q186 Errorless 3. Conservation of Energy and Momentum MCQ
An object of mass 3m splits into three equal fragments. Two fragments have velocities $v\hat{j}$ and $v\hat{i}$ . The velocity of the third fragment is
A.
$v(\hat{j}-\hat{i})$
B.
$v(\hat{i}-\hat{j})$
C.
$-v(\hat{i}+\hat{j})$
D.
$\frac{v(\hat{i}+\hat{j})}{\sqrt{2}}$
AFMC 2004; Odisha JEE 2008 Q187 Errorless 3. Conservation of Energy and Momentum MCQ
A rifle bullet loses $1/20^{\text{th}}$ of its velocity in passing through a plank. The least number of such planks required just to stop the bullet is
A.
5
B.
10
C.
11
D.
20
DCE 2004 Q188 Errorless 3. Conservation of Energy and Momentum MCQ
A bomb is kept stationary at a point. It suddenly explodes into two fragments of masses 1 g and 3 g. The total K.E. of the fragments is $6.4 \times 10^{4}$ J. What is the K.E. of the smaller fragment
A.
$2.5 \times 10^{4}$ J
B.
$3.5 \times 10^{4}$ J
C.
$4.8 \times 10^{4}$ J
D.
$5.2 \times 10^{4}$ J
Pb. PET 2004 Q189 Errorless 3. Conservation of Energy and Momentum MCQ
If a shell fired from a cannon, explodes in mid air, then
A.
Its total kinetic energy increases
B.
Its total momentum increases
C.
Its total momentum decreases
D.
None of these
DCE 2004 Q190 Errorless 3. Conservation of Energy and Momentum MCQ
A body is moving with a velocity v, breaks up into two equal parts. One of the part retraces back with velocity v. Then the velocity of the other part is
A.
v in forward direction
B.
3v in forward direction
C.
v in backward direction
D.
3v in backward direction
CBSE PMT 2004 Q191 Errorless 3. Conservation of Energy and Momentum MCQ
A ball of mass 2kg and another of mass 4kg 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
A.
$\sqrt{2}:1$
B.
1:4
C.
1:2
D.
$1:\sqrt{2}$
KCET 2004 Q192 Errorless 3. Conservation of Energy and Momentum MCQ
A bullet moving with a speed of $100 \, ms^{-1}$ can just penetrate two planks of equal thickness. Then the number of such planks penetrated by the same bullet when the speed is doubled will be
A.
4
B.
8
C.
6
D.
10
AIEEE 2004; BHU 2006 Q193 Errorless 4. Power MCQ
A body of mass m accelerates uniformly from rest to $v_{1}$ in time $t_{1}$ . As a function of time t, the instantaneous power delivered to the body is
A.
$\frac{mv_{1}t}{t_{1}}$
B.
$\frac{mv_{1}^{2}t}{t_{1}}$
C.
$\frac{mv_{1}t^{2}}{t_{1}}$
D.
$\frac{mv_{1}^{2}t}{t_{1}^{2}}$
UPSEAT 2004 Q194 Errorless 5. Elastic and Inelastic Collision MCQ
Four smooth steel balls of equal mass at rest are free to move along a straight line without friction. The first ball is given a velocity of 0.4 m/s. It collides head on with the second elastically, the second one similarly with the third and so on. The velocity of the last ball is
A.
0.4m/s
B.
0.2m/s
C.
0.1m/s
D.
0.05m/s
DCE 2004 Q195 Errorless 5. Elastic and Inelastic Collision MCQ
Two balls at same temperature collide. What is conserved
A.
Temperature
B.
Velocity
C.
Kinetic energy
D.
Momentum
BCECE 2004; J & K CET 2006 Q196 Errorless 5. Elastic and Inelastic Collision MCQ
A body of mass M moves with velocity v and collides elastically with a another body of mass m (M>>m) at rest then the velocity of body of mass m is
A.
v
B.
2v
C.
v/2
D.
Zero
IIT-JEE (Screening) 2004; J & K CET 2006 Q197 Errorless 8. Graphical Questions MCQ
A particle is placed at the origin and a force $F = kx$ is acting on it (where $k$ is positive constant). If $U(0) = 0$ , the graph of $U(x)$ versus $x$ will be (where $U$ is the potential energy function)
A.
B.
C.
D.
MP PET 2003 Q198 Errorless 1. Work Done by Constant Force MCQ
A body of mass 5 kg is placed at the origin, and can move only on the x-axis. A force of 10 N is acting on it in a direction making an angle of $60^{\circ}$ with the x-axis and displaces it along the x-axis by 4 metres. The work done by the force is
A.
2.5 J
B.
7.25 J
C.
40 J
D.
20 J
MP PET 2003 Q199 Errorless 3. Conservation of Energy and Momentum MCQ
The potential energy of a weight less spring compressed by a distance $a$ is proportional to
A.
$a$
B.
$a^2$
C.
$a^{-2}$
D.
$a^0$
CBSE PMT 2003; KCET 2012 Q200 Errorless 3. Conservation of Energy and Momentum MCQ
A stationary particle explodes into two particles of a masses $m_{1}$ and $m_{2}$ which move in opposite directions with velocities $v_{1}$ and $v_{2}$ . The ratio of their kinetic energies $E_{1}/E_{2}$ is
A.
$m_{1}/m_{2}$
B.
1
C.
$m_{1}v_{2}/m_{2}v_{1}$
D.
$m_{2}/m_{1}$