Two tall buildings are 30m apart. The speed with which a ball must be thrown horizontally from a window 150m above the ground in one building so that it enters a window 27.5m from the ground in the other building is: (. Take g=9.8msec- 2 )

Question

Two tall buildings are 30m apart. The speed with which a ball must be thrown horizontally from a window 150m above the ground in one building so that it enters a window 27.5m from the ground in the other building is: (. Take g=9.8msec- 2 ) (A) 2ms- 1 (B) 6ms- 1 (C) 4ms- 1 (D) 8ms- 1

Tardigrade Admin · Accepted Answer

Horizontal projection from height R=√(2 H/g)⋅ u 30=√(2 × 122 . 5/9 . 5)u 30=5× 4 u=6ms- 1

Q. Two tall buildings are $30 m$ apart. The speed with which a ball must be thrown horizontally from a window $150 m$ above the ground in one building so that it enters a window $27.5 m$ from the ground in the other building is: $($ Take $g = 9.8 m se c^{- 2}$ )

$2 m s^{- 1}$

$6 m s^{- 1}$

$4 m s^{- 1}$

$8 m s^{- 1}$

Horizontal projection from height
$R = \frac{2 H}{g} \cdot u$
$30 = \frac{2 \times 122.5}{9.5} u$
$30 = 5 \times 4$
$u = 6 m s^{- 1}$

Q. Two tall buildings are 30m apart. The speed with which a ball must be thrown horizontally from a window 150m above the ground in one building so that it enters a window 27.5m from the ground in the other building is: ( Take g=9.8msec−2 )

2ms−1

6ms−1

4ms−1

8ms−1