How Fast Does a Ball Travel When Dropped from a Height?

[Physics-Pure]

Homework Statement

A ball of mass 0.163 kg is dropped from a
height 1.89 m above the ground.
The acceleration of gravity is 9.8 m/s^2
Neglecting air resistance, determine the
speed of the ball when it is at a height 0.997 m
above the ground.
Answer in units of m/s

Homework Equations

Gravitational Energy = Kinetic Energy

Mass x Acceleration From Gravity x Height = 1/2 (mass)x(velocity)^2

Acceleration From Gravity x Height = 1/2 (velocity)^2 [mass cancels]

The Attempt at a Solution

(9.8 m/s^2) x (1.89m) = 1/2 (velocity)^2

Velocity^2 = 2[(9.8 m/s^2) x (1.89m)]

Velocity = ~6.08 m/s

 

[voko]

Gravitational Energy = Kinetic Energy

Mass x Acceleration From Gravity x Height = 1/2 (mass)x(velocity)^2

This is correct only when one kind of energy is converted entirely into another. Which is not the case in this problem. What equation should you really use?

 

[Physics-Pure]

Vf = sqrt 2a delta y?

 

[azizlwl]

Homework Statement

A ball of mass 0.163 kg is dropped from a
height 1.89 m above the ground.
The acceleration of gravity is 9.8 m/s^2
Neglecting air resistance, determine the
speed of the ball when it is at a height 0.997 m
above the ground.
Answer in units of m/s
[]

Check the height.