A ball rolls down a ramp of height h. If it starts from rest, what is its final
Practice Questions
Q1
A ball rolls down a ramp of height h. If it starts from rest, what is its final velocity at the bottom?
√(gh)
√(2gh)
√(3gh)
√(4gh)
Questions & Step-by-Step Solutions
A ball rolls down a ramp of height h. If it starts from rest, what is its final velocity at the bottom?
Correct Answer: v = √(2gh)
Step 1: Understand that the ball starts from rest, which means its initial velocity is 0.
Step 2: Recognize that the ball is rolling down a ramp, which means it is losing potential energy and gaining kinetic energy.
Step 3: Identify the height of the ramp as 'h'. This height represents the potential energy the ball has at the top.
Step 4: Use the principle of conservation of energy, which states that the total energy at the top equals the total energy at the bottom.
Step 5: At the top, the ball has potential energy given by the formula PE = mgh, where m is mass, g is the acceleration due to gravity, and h is the height.
Step 6: At the bottom, all the potential energy has converted into kinetic energy (KE), which is given by the formula KE = 0.5 * m * v^2, where v is the final velocity.
Step 7: Set the potential energy equal to the kinetic energy: mgh = 0.5 * m * v^2.
Step 8: Cancel the mass (m) from both sides of the equation since it is the same on both sides: gh = 0.5 * v^2.
Step 9: Rearrange the equation to solve for v^2: v^2 = 2gh.
Step 10: Take the square root of both sides to find the final velocity: v = √(2gh).
Conservation of Energy – The principle that energy cannot be created or destroyed, only transformed from one form to another.
Kinetic and Potential Energy – Understanding the conversion of gravitational potential energy at height h into kinetic energy as the ball rolls down.
Kinematics – The study of motion, which includes understanding velocity and acceleration.