Conservation of Mechanical Energy NEET Questions

Physics - Work, Energy, and Power

Conservation of Mechanical Energy MCQ Questions


7.
A block attached to a spring (spring constant k) is extended by xm and released from rest on a frictionless surface. At equilibrium position x = 0, the speed vm is:
A.
vm = √(k/m) · xm
B.
vm = √(2k/m) · xm
C.
vm = k·xm/m
D.
vm = xm · √(m/k)
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ANSWER :
A. vm = √(k/m) · xm
8.
A car of mass 1000 kg moving at 5 m/s collides with a spring (k = 5000 N/m) on a frictionless surface. Maximum compression of spring is approximately:
A.
√5 ≈ 2.24 m
B.
1 m
C.
5 m
D.
0.1 m
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ANSWER :
A. √5 ≈ 2.24 m
9.
The total mechanical energy of a system is conserved when:
A.
Only kinetic forces act
B.
Only conservative forces do work
C.
Non-conservative forces also do work
D.
The system is at rest
😑 View Answer Rough Work Error
ANSWER :
B. Only conservative forces do work
10.
For a spring-mass system undergoing SHM on a frictionless surface, which graph best describes the variation of KE and PE with displacement x?
A.
Both KE and PE are linear in x
B.
KE is parabolic; PE is constant
C.
PE is parabolic; KE is an inverted parabola; their sum is constant
D.
Both KE and PE are constant
😑 View Answer Rough Work Error
ANSWER :
C. PE is parabolic; KE is an inverted parabola; their sum is constant
11.
A ball of mass m is released from height H on a frictionless inclined plane. At height h (h < H), its speed is:
A.
√(2gH)
B.
√(2gh)
C.
√(2g(H−h))
D.
√(g(H−h))
😑 View Answer Rough Work Error
ANSWER :
C. √(2g(H−h))
12.
In which of the following cases is mechanical energy NOT conserved?
A.
A ball falling freely under gravity
B.
A block sliding on a frictionless inclined plane
C.
A spring-mass system on a frictionless surface
D.
A block sliding on a rough horizontal surface
😑 View Answer Rough Work Error
ANSWER :
D. A block sliding on a rough horizontal surface