Mr. Laudari is sliding down a ramp. Energy. Question 2.

Question – Source: Yahoo! Answers !

Mr. Laudari is sliding down a ramp. When he reaches the end of the ramp, he travels straight back up to a point 4.00 m above the ground. Ignoring friction and air resistance, how fast was Mr. Laudari moving at the beginning?
The original height was 3m.

Solution.

Let’s use the Law of Conservation of Energy

Ep – Mechanical potential energy ; Ek – Mechanical Kinetic energy ;

1 – beginning ; 2 – end ;

So, the equation will be:

Ek1 + Ep1 = Ep2 ;

Formulas : Ep =m *g * h ; Ek = m *v^2 / 2;

m*v^2/2 + m*g*h1 = m*g*h2

v = SQRT (2*g*(h2-h1)) = SQRT(2*9.81*(4-3)) = 4.43 m/s

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