The height of a slope making an angle of 30 degrees with the horizontal is 36 m. What is the velocity of an object that slides down from the top.

Expert Answers

An illustration of the letter 'A' in a speech bubbles

You need to apply the principle of conservation of mechanical energy such that: `mgh = (mv^2)/2 =gt 2gh = v^2 =gt v = +-sqrt(2gh).`

Considering the motion of object frictionless, hence `v = sqrt(2gh).`

The problems provides the value of height, hence the angle made by slope to x axis...

Unlock
This Answer Now

Start your 48-hour free trial to unlock this answer and thousands more. Enjoy eNotes ad-free and cancel anytime.

Start your 48-Hour Free Trial

You need to apply the principle of conservation of mechanical energy such that: `mgh = (mv^2)/2 =gt 2gh = v^2 =gt v = +-sqrt(2gh).`

Considering the motion of object frictionless, hence `v = sqrt(2gh).`

The problems provides the value of height, hence the angle made by slope to x axis is of no need in this problem. You need to know the angle only if the length of slope is known but the height is not given.

Substituting  is`9.8 m/(s^2)`  for g and 36 m for h yields:v = `sqrt(2*9.8*36) ` => `v~~ 26.56 m/s` 

Hence, evaluating the velocity of object sliding down from the top of slop yields: v~~ 26.56 m/s.

Approved by eNotes Editorial Team