physics

posted by .

A stunt driver wants to make his car jump over eight cars parked side by side below a horizontal ramp.

(a) With what minimum speed must he drive off the horizontal ramp? The vertical height of the ramp is 1.5m above the cars, and the horizontal distance he must clear is 20m.

(b) If the ramp is now tilted upward, so that "takeoff angle" is 10 degrees above the horizontal, what is the new minimum speed?

  • physics -

    this is from that white book that i'm also using...

    the odd answers in the book are in the back in which this problem is one I belive

  • physics -

    You know the horizontal distance it must go.

    Horizontal distance=vi*time
    verticalpositionfinal=verticalpositioninitial -4.9 t^2
    0=1.5-4.9 t^2 solve for t, then put that into the horizontal distance equation and solve for vi.

    Now if you tilt it, then the vihoriontal is viCos10, and vivertical is not zero, but ViSin10.

    Work it the same way, it is a little tricker on the algebra, but it works cleanly.

  • physics -

    I don't know how the author of the Giancoli text reached 20 m/s as the answer to the second part of this questions. Nevertheless, I do know that the solution Bobpursley suggests here doesn't work. I find it interesting that there isn't one straightforward solution to this question on the entire internet. I've been working on the problem for two days, and none of the strategies I have tried give me 20 m/s.

  • physics -

    To call the algebra on this question convuluted is a profound understatement. Nevertheless, I have solved it.

    The range equals 20 meters and the initial velocity of the car along the x-axis is 0.98Vi (or the Vicos10). Since the combined time the car travels up and down on the y-axis equals the time the car travels the entire way along the x-axis, you can set the equation as follows:

    time = time

    or

    20 / 0.98Vi = time on y-axis

    Divide 20 by 0.98 to find that the ratio of the initial velocity is:

    20.4 / Vi

    ...or more simply put, the initial velocity if 20 m/s.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Physics

    Ok the problem I'm doing has two parts I know how to do part a and got the right answer I think... I do not know how to do part b Here's the problem A student driver wants to make his car jump over 8 cars parked side by side below …
  2. physics

    A motorcycle daredevil is attempting to jump across as many buses as possible (see the drawing). The takeoff ramp makes an angle è = 18.0° above the horizontal, and the landing ramp is identical to the takeoff ramp. The buses are …
  3. college physic

    A stunt driver wants to make his car jump over 8 cars parked side by side below a horizontal ramp.(a)With what minimum speed must he drive off the horiontal ramp?
  4. college physic

    A stunt driver wants to make his car jump over 8 cars parked side by side below a horizontal ramp.(a)With what minimum speed must he drive off the horiontal ramp?
  5. physics

    A stunt driver wants to make his car jump over eight cars parked side by side below a horizontal ramp a)With what minimum speed must he drive off the horizontal ramp?
  6. Physics

    A stunt driver wants to make his car jump over 8 cars parked side by side below a horizontal ramp. A)With what minimum speed must he drive off the horizontal ramp?
  7. Physics

    A stunt motorcyclist is attempting to jump over a river of width 60m using a ramp which is inclined at 30 degrees to the horizontal. Assume the height of the ramp is small enough to be ignored in the calculations. a) What is the minimum …
  8. physics

    A motorcycle daredevil is attempting to jump across as many buses as possible (see the drawing). The takeoff ramp makes an angle θ = 16.8° above the horizontal, and the landing ramp is identical to the takeoff ramp. The buses …
  9. physics

    A physics professor moonlights as a daredevil jumping things on a motorbike. His next stunt will be to jump the oldman river on his motorcycle. The ramp is being built 100 m above the river and made an angle of 50.0 o relative to the …
  10. physics

    A physics professor moonlights as a daredevil jumping things on a motorbike. His next stunt will be to jump the oldman river on his motorcycle. The ramp is being built 100 m above the river and made an angle of 50.0 o relative to the …

More Similar Questions