# Conservation of Energy Help

**1. The problem statement, all variables and given/known data**

I have a homework assignment that I am stuck on using the attached table.

Problem 1: I have to find the velocity when given the mass and height.

Problem 2: Then I have to find the height when given the velocity and mass.

**2. Relevant equations**

P.E. = m*g*h

K.E. = 1/2*m*v^2

Mass = 1kg

Gravity = 9.8m/s

**3. The attempt at a solution**

P.E.(1) = 1kg * 9.8m/s * .5m

P.E.(1) = 4.9J

P.E.(2) = 1kg * 9.8m/s * .2m

P.E.(2) = 1.96J

K.E.(1) = 0m/s

K.E.(2) = 1/2*1kg*(.8m)^s

K.E.(2) = .32J

K.E.(1) + P.E.(1) = K.E.(2) + P.E.(2)

0m/s+4.9J = 1/2*1kg*v^2 + 0J

4.9J = .5*v^2

4.9J*.5=v^2

√2.45J=v^2

2.45 m/s = v

I am not sure about how to get the height.

Thank you for any help

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