Question

its velocity not acceration please answer the question by the given question only

Answer 1

Answer:

Option B ( 20 m)

Explanation:

Previous Knowledge:

•         Motion in 1D formulas

Or

• Projectile motion

            Projectile motion is the motion of an object thrown or projected into the air, subject to only the acceleration of gravity. The object is called a projectile, and its path is called its trajectory.

• Time of flight

The time of flight of an object is the total time taken by the projectile to reach the ground, which is found by:

              T = 2u sinθ / g

• Maximum Height

The maximum height is reached when Vy=0. Using this we can rearrange the velocity equation to find the time it will take for the object to reach maximum height.

            H (max) = u²sin²θ /2 g

Solution:

Dear Student,

There are two ways to solve this problem, is by using Motion in 1D formulas or by the knowledge of projectile motion.

To make it easier, I'm using Motion in 1D formulas,

Given,  u = 20m/s

            v = 0 m/s ( as it comes to rest)

            g = 10m/s² (but as it's going upwards g is -ve)

To Find:  s , maximum height

   

Using, v² = u² + 2gs  ( a = g)

   =>    0  = 20² + 2 (-10) s

   =>    0  = 400 + -20 s

  =>  -400/-20  = s

  =>  s = 20 m

Therefore, Option B would be correct.

Thanks!

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