Upon what Does the Final Speed of a Trolley Depend as It Goes Down a Ramp?

Upon what does the final speed of a trolley depend?
Aim- The Aim of this investigation is to discover how certain variables affect the final speed of a trolley. I will investigate this using an elevated ramp and a trolley to down it. I will investigate the relationship between the height of a ramp (which a trolley is rolled down) and the trolley's final speed as it comes off the ramp.
Hypothesis- I predict that as the height of the ramp is increased the final speed of the trolley will also be increased: this can be both measured and easily seen. …