Answer: 20 meters
Explanation:
This situation is related to vertical motion, especifically an object in free fall, and the parametric equation that describes this motion is:
Where:
is the stone's final height
is the stone's initial height
is the initial speed of the stone
is the time the stone is falling
is the acceleration due gravity
Isolating according to the given information:
Finally:
This is the distance the stone fell
C. Forces act in pairs, so when the red ball pushes the blue ball forward, the the blue ball exerts an equal and opposite force on the red ball.
The second runner must run 3.3m/s. If the leading runner is 1.5 seconds ahead and there are 30m left, the second runner would need to run slightly faster than the lead in order to finish at the same time. To calculate this I did 30/1.5 which gave me 0.05. I added this onto the speed of the lead runner to get 3.3m/s :)