NEET-XII-Physics
05: Newton's Laws of Motion
- #10Two objects A and B are thrown upward simultaneously with the same speed. The mass of A is greater than that of B. Suppose the air exerts a constant and equal force of resistance on the two bodies.
(a) The two bodies will reach the same height.
(b) A will go higher than B.
(c) B will go higher than A.
(d) Any of the above three may happen depending on the speed with which the objects are thrown.digAnsr: bAns : (b) A will go higher than B.
Let the air exert a constant resistance force = F (in downward direction).
Acceleration of particle A in downward direction due to air resistance, aA = F/mA.
Acceleration of particle B in downward direction due to air resistance, aB = F/mB.
mA > mB
aA < aB
`` S=ut+\frac{1}{2}a{t}^{2}``
`` \,\mathrm{\,So \,},{H}_{A}=ut-\frac{1}{2}({a}_{A}+g){t}^{2}``
`` {H}_{B}=ut-\frac{1}{2}({a}_{B}+g){t}^{2}``
`` {H}_{A}>{H}_{B}``
Therefore, A will go higher than B.