posted by nicole on .
if the height of a playground slide is kept constant, will the length of the slide or the presence of bumps make any difference in the final speed of kids playing on it if a) the slide is frictionless b) the slide has kinetic friction?
a) if the slide is frictionless, length or bumps wouldn't matter because it acts like a free fall
b) if the slide had kinetic friction, it would work against the speed going down the slide so it would have an effect
a) the slide is frictionless?
The answer No but why?
because of the energy conversation rule
Potential Energy(PE)=Kinetic Energy(KE)
this means Potential Energy of the child on the top of the slid is the same as his Kinetic Energy on the bottom.
Remember KE = 0.5*m(mass of child)*V^2(velocity of child)
PE=m(mass of child)*g(gravity 9.8 on Earth)*h(height of the playground)
When there is no friction means nothing stopping the child of sliding so the velocity will not decrease and i can say it will increas.
b) the slide has kinetic friction?
I think for this question he means the slid has friction so in this case the velocity would be effected ... ust think other way if you push your cup of coffee on a kitchen table you give it a force and due to newton's low the cup will move to the direction of the force applied so if you push the same cup with same force but in a different surface lets say on a carpet it will not move as much as when it was in the kitchen table because friction matters .