Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Physics
Physics
Problem
18. The operating efficiency of a
0.5
A
,
120
V
0.5 \mathrm{~A}, 120 \mathrm{~V}
0.5
A
,
120
V
electric motor that lifts a 9 kg mass against gravity at an average velocity of
0.5
m
/
s
0.5 \mathrm{~m} / \mathrm{s}
0.5
m
/
s
is most nearly (A)
13
%
13 \%
13%
(B)
25
%
25 \%
25%
(C)
53
%
53 \%
53%
(D)
75
%
75 \%
75%
(A)
13
%
13 \%
13%
(B)
25
%
25 \%
25%
(C)
53
%
53 \%
53%
(D)
75
%
75 \%
75%
Browse the problem library