A bullet is fired from a gun at the speed of $$280 \mathrm{~ms}^{-1}$$ in the direction $$30^{\circ}$$ above the horizontal. The maximum height attained by the bullet is
$$\left(g=9.8 \mathrm{~ms}^{-2}, \sin 30^{\circ}=0.5\right)$$:-
A horizontal bridge is built across a river. A student standing on the bridge throws a small ball vertically upwards with a velocity $$4 \mathrm{~m} \mathrm{~s}^{-1}$$. The ball strikes the water surface after $$4 \mathrm{~s}$$. The height of bridge above water surface is (Take $$g=10 \mathrm{~m} \mathrm{~s}^{-2}$$ )
A cricket ball is thrown by a player at a speed of 20 m/s in a direction 30$$^\circ$$ above the horizontal. The maximum height attained by the ball during its motion is
(g = 10 m/s2)
A ball is projected with a velocity, 10 ms$$-$$1, at an angle of 60$$^\circ$$ with the vertical direction. Its speed at the highest point of its trajectory will be