Work Done by a Constant Force and a Variable Force NEET Questions

Physics - Work, Energy, and Power

Work Done by a Constant Force and a Variable Force MCQ Questions


13.
A force of 5 N acts on a 15 kg body initially at rest. The work done by the force during the first second of motion of the body is:
A.
5 J
B.
5/6 J
C.
6 J
D.
75 J
😑 View Answer Rough Work Error
ANSWER :
B. 5/6 J
14.
If Ef and Ei are final and initial total mechanical energies, and Wnc is work by non-conservative forces, then:
A.
Ef − Ei = Wnc
B.
Ef − Ei = 0
C.
Ef + Ei = Wnc
D.
Ef = Ei + KE
😑 View Answer Rough Work Error
ANSWER :
A. Ef − Ei = Wnc
15.
A block slides from the top to the bottom of a rough inclined plane. Compared to a frictionless incline of same height, the speed at the bottom is:
A.
The same
B.
Greater
C.
Less
D.
Zero
😑 View Answer Rough Work Error
ANSWER :
C. Less
16.
A force F = 20 + 10y acts on a particle in the y-direction, where F is in newtons and y is in meters. The work done by this force to move the particle from y = 0 to y = 1 m is:
A.
30 J
B.
5 J
C.
25 J
D.
20 J
😑 View Answer Rough Work Error
ANSWER :
C. 25 J
17.
The work done by the spring force when a block is moved from xi to xf is:
A.
½k(xf² − xi²)
B.
½k(xi² − xf²)
C.
k(xi − xf)
D.
k(xf − xi)²
😑 View Answer Rough Work Error
ANSWER :
B. ½k(xi² − xf²)
18.
A ball is thrown upward and returns to the same point. Work done by gravity is:
A.
2mgh (h = max height)
B.
mgh
C.
Zero
D.
−mgh
😑 View Answer Rough Work Error
ANSWER :
C. Zero