Question

A force produces an acceleration of 4ms in a body of mass m1 and the same force produces an acceleration of 6ms in another body of mass m2. If the same force is applied to (m1+m2), then the acceleration will be:

Answer 1

F=m1a1 F=m2a2
F=m1×4 (a=4m/s) F=m2×6 (a=6m/s)
m1=F/4. m2=F/6
m1+m2=F/4+F/6
m1+m2=5F/12
as F=ma a=F/m
for m we have m1+m2=5F/12
as same force is applied to m1+m2
hence
a=F/m
=a=F/(m1+ m2)
=a=F/(5F/12)
=a=12/5
=a=2.4ms