Answer:
a) "gravitation" is the force causing you to go down a waterslide
b) It is "fluid friction" as a solid object (our body) moves over a fluid (the water)
c) It would become "sliding friction" since two solid surfaces slide over each other
d) fluid friction being the weakest friction, switching to sliding friction means a higher decrease in speed and therefore removing the water from a slide will decrease our speed
You have to move your foot to stop the car so I guess that would be considered work by moving your foot
Using F = Ke
F = 39200×(25÷100) = 39200×0.25
F= 9800N
First the velocity drops to zero in 1.2 secs. In those seconds it went upwards for 7.2 m, then it went from 87.2 to 0m. x-x0=v0*t+1/2*g*t^2 ergo t=sqrt(2x/g) that is 4.1761 s. Finally the total time required is 5.3761 s