Answer:
Explanation:
Given
mass of box 
coefficient of kinetic friction 
coefficient of Static friction 
cart is moving with constant velocity therefore Net Force is zero
Since there is no net acceleration therefore friction force will be zero
mathematically

where 



Answer:
S1 = 1/2 g t^2 distance stone falls in time t
S2 = Vy t - 1/2 g t^2 distance thrown stone rises in time t
H = 49 = S1 + S2 = Vy t
t = 49 / 40 sec time when stones meet
Check:
Stone 1 falls: 1/2 g t^2 = 1/2 * 9.8 * (49 / 40)^2 = 7.35 m
Stone 2 rises : 40 * (49 / 40) - 1/2 * 9.8 (49 / 40)^2 = 41.65 m
The Space Age began on October 4, 1957.
Solution:
The world record for the longest flight by a human cannonball is approximately 200 feet and therefore the human cannon catapult that Bobo would need is one that would be able to propel him with an initial velocity of more than 120 kilometer per hour (more than the speed of the current record holder) with the cannon directed at an angle 45 degrees above the horizonal
Learn more about the projectile motion here:
brainly.com/question/24240176
An eraser, a type of rubber, uses static friction when rubbed across a sheet of paper.