Question

A cannon ball is fired horizontally with a velocity of 50 metre per sec from the top of a cliff 90m high. After how many seconds will it strike the plain at the foot of the cliff? with what velocity will it strike the ground?​

Answer 1

To solve the problem, we use the equations of projectile motion. The cannonball takes approximately 4.28 seconds to hit the ground and has a velocity of 50m/s at impact.

Step-by-step explanation:

To solve this problem, we can use the equations of projectile motion. Since the cannonball is fired horizontally, its initial vertical velocity is zero, so it will only accelerate vertically due to gravity. We can use the equation h = (1/2)gt^2, where h is the height of the cliff (90m), g is the acceleration due to gravity (9.8m/s^2), and t is the time it takes for the cannonball to hit the ground.

Plugging in the values, we get 90 = (1/2)*(9.8)*t^2. Solving for t, we find that it takes approximately 4.28 seconds for the cannonball to strike the ground.

Since the cannonball is fired horizontally, its initial vertical velocity is zero, so its velocity just before hitting the ground will be equal to its horizontal velocity. The horizontal velocity remains constant throughout the motion, so the cannonball will have a velocity of 50m/s just before hitting the ground.