A woman pushes a trunk on a railway platform. she applied a force 100N over 10m distance and reduces the force linearly with distance to 50N . total distance moved by trunk is 20m. draw F-s graph if frictional force is 50N . also calculate work done over 20m
Answers
Explanation:
the plot of the applied force is shown in figure.
At x = 20 m, F = 50 N ( 0). We are given that the frictional force f=50 N. It opposes motion and acts in a direction opposite to F. It is therefore shown on the negative side of the force axis.
The work done by the woman is
WF = area of the rectangle ABCD + area of the trapezium CEID.
= 1000 + 750
= 1750 J
The work done by the frictional force is
W = area of the rectangle AIHJ
= -50 ×20 = -1000 J
The area on the negative side of the force axis has negative sign.
Answer:-1000J
Explanation:we have given that
X=20m
F=50N
We are given frictional force. It is opposite to F
Wf=100*10+1/2(100+50)*10
=1000+750
=1750J
The work done by the frictional force is
Wf=(-50)*20
=-1000J
Ans: The area on the negative side of force axis has a negative sign