# physics help

posted by .

1. A roller coaster car starts from rest and rolls down a frictionless track, reaching speed fv at
the bottom.
a. If you want the car to go two times as fast at the bottom, by what factor must you
increase the height of the track?
b. Does your answer to part (a) depend on whether the track is straight or not? Explain.

2. You release a frictionless cart at the top of each of the 2 ramps. On Ramp B, the cart is
released from rest, but on Ramp A the cart is pushed at the top so that it has some initial
velocity. The ramps have the same height as each other at start and finish. One has a small
bump up then down just before the end. The other has a small bump down then up. Which cart has the larger speed at the finish? Why?

• physics help -

1. Twice the speed requires 4 times the kinetic energy. What does that tell you about the height or the top of the track?

2. Forget about the bumps. The car that starts out with kinetic energy (from the push) has more kinetic energy at the bottom.

## Similar Questions

1. ### physics

A car that is initially at rest at the top of a roller-coaster track moves down the track without friction. What must be the maximm initial height from which the car descends so that it will not fly off the 10-m-high circular hill …
2. ### Physic

Just an instant before reaching the very bottom of a semicircular section of a roller coaster ride, the automatic emergency brake inadvertently goes on. Assume the car has a total mass of 850 kg, the radius of that section of the track …
3. ### physics

A 1400kg car starts at rest and rolls down a hill from a height of 12m. (a) how much kinetic energy does the car have at the bottom of the hill?
4. ### physics

The mass of a roller-coaster car, including its passengers, is 481 kg. Its speed at the bottom of the track in the figure below is 20 m/s. The radius of this section of the track is r1 = 24 m. Find the force that a seat in the roller-coaster …
5. ### Physics

At the beginning of a roller coaster ride, the car is lifted to the top of a large hill and released. The speed of the car at the top of the hill is small, so we will assume it to be zero. The car rolls freely down this hill and reaches …
6. ### Physics

At the beginning of a roller coaster ride, the car is lifted to the top of a large hill and released. The speed of the car at the top of the hill is small, so we will assume it to be zero. The car rolls freely down this hill and reaches …
7. ### Physics

At the beginning of a roller coaster ride, the car is lifted to the top of a large hill and released. The speed of the car at the top of the hill is small, so we will assume it to be zero. The car rolls freely down this hill and reaches …
8. ### Physics

A roller-coaster car rolls down a track, reaching a speed of v0 at the bottom. If the height of the track is increased by a factor of 2.00, assuming the track is frictionless, by what factor will the speed at the bottom increase?
9. ### Physics

A 240 kg roller coaster car Rolls over the crest of the roller coaster with a speed of 2.2m/s.if it falls through a vertical height of 12m down the tracks to the bottom of a trough, how fast will it be travelling?
10. ### Physics

A roller coaster car is loaded with passengers and has a mass of 500 kg along with a speed of 18 meters/second at the dip. The radius of curvature of the track at the bottom point of the dip is 12 meters (gravity = 9.8 meters/second2). …

More Similar Questions