Kevin stands at the edge of a cliff, holding one ball in each hand. He throws one of the balls straight up with speed v, and at the same time he throws the other ball straight down, also with speed v. Ignoring air resistance, which ball hits the ground with greater speed?
a)ball thrown up
b)ball thrown down
c)both will hit the ground with the same speed.
I was thinking of ball thrown up, because it will be basically thrown from a higher height. I am a little confused.
Thanks in advance
Since air resistance was ignored, both of them will hit the ground at the same time.
To determine which ball hits the ground with greater speed, let's analyze the motion of each ball.
When Kevin throws the ball straight up, it will experience an initial upward velocity and then gradually slow down due to the gravitational force acting in the opposite direction. Eventually, it will reach its highest point and start coming back down. Throughout its entire trajectory, the ball will continually decrease in speed until it reaches the ground.
On the other hand, when Kevin throws the ball straight down, it will experience an initial downward velocity. Due to the gravitational force, the ball will accelerate as it falls toward the ground. When it reaches the ground, it will have gained additional speed from this acceleration.
Considering this information, we can conclude that the ball thrown down will hit the ground with a greater speed than the ball thrown up. The ball thrown up slows down as it rises and then accelerates downward due to gravity. However, the ball thrown down is already moving downward from the start and accelerates further due to gravity. Since the ball thrown down undergoes acceleration while falling, it will have a greater final speed when it hits the ground compared to the ball thrown up.
Therefore, the correct answer is:
b) The ball thrown down.