A ball projected from ground vertically upward is at same height at time t1 and t2. The speed of projection of ball is [Neglect the effect of air resistance]

Question

A ball projected from ground vertically upward is at same height at time t1 and t2. The speed of projection of ball is [Neglect the effect of air resistance] (A) g[t2-t1] (B) (g[t1+t2]/2) (C) (g[t2-t1]/2) (D) g[t1+t2]

Tardigrade Admin · Accepted Answer

t1+t2= total time of flight t1+t2=2 T T=(t1+t2/2), also T=(u/g) (u/g)=(t1+t2/2) ⇒ u=(1/2) g(t1+t2)

Q. A ball projected from ground vertically upward is at same height at time $t_{1}$ and $t_{2}$ . The speed of projection of ball is [Neglect the effect of air resistance]

$g [t_{2} - t_{1}]$

$\frac{g [ t _{1} + t _{2} ]}{2}$

$\frac{g [ t _{2} - t _{1} ]}{2}$

$g [t_{1} + t_{2}]$

$t_{1} + t_{2} =$ total time of flight
$t_{1} + t_{2} = 2 T$
$T = \frac{t _{1} + t _{2}}{2}$ , also $T = \frac{u}{g}$
$\frac{u}{g} = \frac{t _{1} + t _{2}}{2}$
$\Rightarrow u = \frac{1}{2} g (t_{1} + t_{2})$

Q. A ball projected from ground vertically upward is at same height at time t1​ and t2​. The speed of projection of ball is [Neglect the effect of air resistance]

g[t2​−t1​]

2g[t1​+t2​]​

2g[t2​−t1​]​

g[t1​+t2​]