A car is moving horizontally along a straight line with a uniform velocity of 25 m s -1. A projectile is to be fired from this car in such a way that it will return to it after it has moved 100 m. The speed of the projection must be

Question

A car is moving horizontally along a straight line with a uniform velocity of 25 m s -1. A projectile is to be fired from this car in such a way that it will return to it after it has moved 100 m. The speed of the projection must be (A) 10 m s -1 (B) 20 m s -1 (C) 15 m s -1 (D) 25 m s -1

Tardigrade Admin · Accepted Answer

T=(100/25)=4 s ⇒ (2 u sin θ/g)=4 ⇒ u sin θ=20 ms -1

Q. A car is moving horizontally along a straight line with a uniform velocity of $25 m s^{- 1}$ . A projectile is to be fired from this car in such a way that it will return to it after it has moved $100 m$ . The speed of the projection must be

$10 m s^{- 1}$

$20 m s^{- 1}$

$15 m s^{- 1}$

$25 m s^{- 1}$

$T = \frac{100}{25} = 4 s$
$\Rightarrow \frac{2 u s i n θ}{g} = 4$
$\Rightarrow u sin θ = 20 m s^{- 1}$

Q. A car is moving horizontally along a straight line with a uniform velocity of 25ms−1. A projectile is to be fired from this car in such a way that it will return to it after it has moved 100m. The speed of the projection must be

10ms−1

20ms−1

15ms−1

25ms−1