A ball is thrown horizontally from the top of a cliff 80 m high. How far from th
Practice Questions
Q1
A ball is thrown horizontally from the top of a cliff 80 m high. How far from the base of the cliff will it land? (Assume g = 10 m/s² and horizontal speed = 20 m/s)
20 m
40 m
60 m
80 m
Questions & Step-by-Step Solutions
A ball is thrown horizontally from the top of a cliff 80 m high. How far from the base of the cliff will it land? (Assume g = 10 m/s² and horizontal speed = 20 m/s)
Correct Answer: 80 m
Step 1: Identify the height of the cliff, which is 80 meters.
Step 2: Use the formula to calculate the time it takes for the ball to fall: time = √(2h/g), where h is the height and g is the acceleration due to gravity (10 m/s²).
Step 3: Plug in the values: time = √(2 * 80 / 10).
Step 4: Calculate the value inside the square root: 2 * 80 = 160, and 160 / 10 = 16.
Step 5: Find the square root of 16, which is 4 seconds. This is the time it takes for the ball to hit the ground.
Step 6: Now, calculate the horizontal distance the ball travels while it is falling. Use the formula: distance = speed * time.
Step 7: Plug in the values: distance = 20 m/s * 4 s.
Step 8: Calculate the distance: 20 * 4 = 80 meters. This is how far from the base of the cliff the ball will land.
Projectile Motion – The question tests understanding of projectile motion, specifically the separation of vertical and horizontal components of motion.
Free Fall – It assesses the ability to calculate the time of free fall using the height of the cliff and gravitational acceleration.
Horizontal Motion – It evaluates the understanding of constant horizontal velocity and how it relates to distance traveled over time.
