Two bodies are projected from ground with equal speed 20 m/s from the same position in the same vertical plane to have equal range but at different angles above the horizontal. If one of the angle is 30° the sum of their maximum heights is (assume g=10 m/s2 )

Question

Two bodies are projected from ground with equal speed 20 m/s from the same position in the same vertical plane to have equal range but at different angles above the horizontal. If one of the angle is 30° the sum of their maximum heights is (assume g=10 m/s2 ) (A)  400 m  (B)  20 m  (C)  30 m  (D)  40 m

Tardigrade Admin · Accepted Answer

h max = ( u2 / 2 g ) ∴ h max = ( ( 20)2 / 2 × 10 ) = 20 m For the second body also h max = 20 m ∴ Sum of maximum heights = 20 m + 20 m = 40 m

Q. Two bodies are projected from ground with equal speed $20 m / s$ from the same position in the same vertical plane to have equal range but at different angles above the horizontal. If one of the angle is $3 0^{\circ}$ the sum of their maximum heights is (assume $g = 10 m / s^{2}$ )

$400 m$

$20 m$

$30 m$

$40 m$

$h_{m a x} = \frac{u ^{2}}{2 g}$
$∴ h_{m a x} = \frac{( 20 ) ^{2}}{2 \times 10} = 20 m$
For the second body also $h_{m a x} = 20 m$
$∴$ Sum of maximum heights $= 20 m + 20 m$
$= 40 m$

Q. Two bodies are projected from ground with equal speed 20m/s from the same position in the same vertical plane to have equal range but at different angles above the horizontal. If one of the angle is 30∘ the sum of their maximum heights is (assume g=10m/s2 )

400m

20m

30m

40m