Question

Question2. A force of 100 N gives a body of mass m, an acceleration of 5ms-²?.The same
force can give an acceleration of 40ms-²? to another body of mass m .If both bodies are tied
together and acted upon by same force, what is the acceleration of combination.​

Answer 1

This question is of class nine NCERT book chapter Force and Laws of Motion
But still I can tell you if you want the answer.
Case 1
F=100N
a=5m/s square
F=m/a
100N=m/5m/s square
100*5=m
m=500kg

Case 2
F=100N
a=40m/a square
F=m/a
100N=m/40m/a square
100*40=m
m=4000kg

If both the masses were tied together,total mass is 500kg+4000kg=4500kg.

F=100N
m=4500kg
a=?
F=m/a
100N=4500/a
a=4500/100
a=45m/a square