The kinetic energy of an object is directly proportional to its mass, and to the square of its velocity.
No.
The acceleration of gravity on or near Earth's surface is 9.8 m/s² ,
not 20 m/s² .
If it were 20 m/s², then you would weigh almost exactly double
what you really weigh now.
First figure shows the object position
Second shows the image position
Third shows the focal length.
Answer: 3.49 s
Explanation:
We can solve this problem with the following equation of motion:
(1)
Where:
is the final height of the ball
is the initial height of the ball
is the initial velocity (the ball was dropped)
is the acceleratio due gravity
is the time
Isolating :
(2)
(3)
Finally we find the time the ball is in the air:
(4)
