Question

ball is projected horizontal with a velocity of 5 ms-1 from the top of a building 19.6 m high. How long will the ball take to hit the ground?

Solution

Correct option is

s

 

The time taken to reach the ground is independent of the horizontal velocity of projection. Since the initial downward velocity is zero (the initial velocity has only a horizontal component), the time of flight is given by

                         

SIMILAR QUESTIONS

Q1

The maximum height attained by a projectile and its horizontal range are equal to each other if the projectile is projected at an angle θ given by

Q2

When a projectile is at the highest point of its trajectory, the directions of its velocity and acceleration are

Q3

bomb is dropped from an aero plane when it is at a height h directly above a target. If the aero plane is moving horizontally at a speed v, the distance by which the bomb will miss the target is given by

Q4

missile is fired for maximum range at your town from a place in the enemy country 100 km away from your town. If the missile is first detected at its half – way point, how much warning time will you have? Take g = 10 ms-2.

Q5

cricketer can throw a ball to a maximum horizontal distance of 100 m. With the same effort, he throws the ball vertically upwards. What is the maximum height attained by the ball?

Q6

From the top of a tower of a height 40 m, a ball is projected upwards with a speed of 20 m/s at an angle of elevation of 30°. The ratio of the total time taken by the ball to hit the ground to its time of flight (time taken to come back to the same elevation) is (Take g = 10 m/s2)