Question

Two bodies of masses M and m(M>m) are allowed to fall from the same height. If

Answer 1

$\sf{\pink{\underline{\underline{\blue{QUESTION:-}}}}}$

✨ ASSERTION :-

• Two bodies of masses M and m (M>m) are allowed to fall from the same height . If the air resistance for each be the same then both the bodies will reach the earth simultaneously .

✨ REASON :-

• For same air resistance, acceleration of both the bodies will be same .

[A] If both assertion and reason are true and reason is the correct explanation of assertion .

[B] If both assertion and reason are true but reason is not the correct explanation of assertion .

[C] If assertion is true but reason is false

[D] If both assertion and reason are false

$\sf{\pink{\underline{\underline{\blue{SOLUTION:-}}}}}$

✍️ The force acting on the body of mass M are [its weight] ‘Mg’

• Mg are acting vertically downwards

• And air resistance F acting vertically upward .

Hence,

$\rm{\green{Acceleration\:of\:the\:body\:(a)\:=\:\dfrac{Mg\:-\:F}{M}\:}}$

$\rm{\implies\:Acceleration\:of\:the\:body\:(a)\:=\:g\:-\:\dfrac{F}{M}\:}$

⚡ Now, M > m therefore, the body with larger mass will have greater acceleration and it will reach the ground first .

$\green\bigstar\:\rm{\gray{\overbrace{\underbrace{\purple{\therefore\:[D]\:Both\:Assertion\:and\:Reason\:\atop{are\:incorrect\:.}}}}}}$