Question

What is the final velocity(v)? Given: u=0, mass of the object=10kg, BC=10m, ABC is right-angled, and angle CAB=30 degrees. Refer to the image:

Answer 1

`v = 14 m/s`

Explanation:

I assume the center of mass of the block descends 10 m and there is not friction.

This can be solved using the principle of conservation of energy. The gravitational potential energy when at the top was

`GPE = m*g*h`

After reaching the bottom, the kinetic energy would be 980 J. We can get the velocity using the formula for KE.
`KE = 1/2 * m * v^2`

`GPE = KE`
`cancel(m)*g*h = 1/2 * cancel(m) * v^2`

`v^2 = 2*g*h = 2 * 9.8 m/s^2 * 10 m = 196 m^2/s^2`

`v = sqrt(196 m^2/s^2) = 14 m/s`

I hope this helps,
Steve