LIVE Course for free

Rated by 1 million+ students
Get app now
0 votes
in Physics by (68.4k points)
closed by
Two persons manage to push a motorcar of mass`1200kg` at a uniform velocity along a level road. The same motorcar can be pushed by three persons to produce an acceleration of `0.2m//s^(2)`. With what force does each person push the motorcar? (Assume that all persons push the motorcar with the same muscular effort).

1 Answer

0 votes
by (66.1k points)
selected by
Best answer
Suppose each person applies a force F to push the motorcar.
So, Total force applied by two persons=F+ F
=2F ....(1)
Since this force (2F) gives a uniform velocity to the motorcar along a level road (where work is done only against the force of friction), so the force 2F can be taken as being equal to the force of friction f between the motorcar and the road. That is,
Force of friction, f=2F ....(2)
Now, when three persons apply force to push the motorcar, then:
Total force applied by three persons=F+ F+F
=3F .....(3)
Now, the total force applied by three persons is 3F whereas the opposing force of friction is f. So,
Force that produces acceleration=3F-2F ...(4)
But from equation (2), we have f=2F.So,
Force that produces acceleration=3F-2F
or Force that produces acceleration=F
Now, Force =mass `xx` acceleration
F=240 N
Thus, each person pushes the motorcar with a force of 240 newtons.

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.