Projectile Motion: Skateboarder on a Ramp

In summary, the skateboarder starts at a 1.0-meter high, 30-degree ramp with a speed of 7.9 m/s. The skateboard wheels have no friction. Using the equations x=x0+v0t+.5(a)(t2) and v=v0+at, the distance from the end of the ramp to where the skateboarder touches down is 6.913 meters. There was confusion about the initial vertical velocity and the ground level, but it was clarified that the 7.9 m/s is at the bottom of the ramp, not the end.
  • #1
DRC12
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Homework Statement


A skateboarder starts up a 1.0--high, 30 ramp at a speed of 7.9 . The skateboard wheels roll without friction. How far from the end of the ramp does the skateboarder touch down?


Homework Equations



x=x0+v0t+.5(a)(t2)
v=v0+at

The Attempt at a Solution


This question seems pretty straight forward and I've found an answer but the website we use says it's wrong. First I found vx=7.9cos(30)=6.84 and vy=7.9sin(30)=3.95. I tried finding maximum y by solving vy=0=-9.8*t1 then t1=.405 and plugging that into y=1.8 then finding t2 when y=0 and y0=1.8 to get t2=.605 so ttotal=1.01 and plugging that into x=6.913
 
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  • #2
A skateboarder starts up a 1.0--high, 30 ramp at a speed of 7.9 . The skateboard wheels roll without friction. How far from the end of the ramp does the skateboarder touch down?
-------------------
My understanding that it starts off a flat ramp top.
I do not understand whether the friction has any factor in the calculation.
With zero initial vertical velocity, in my calculation the distance from the base is 1.8m
 
  • #3
sorry 30 ramp is supposed to be 30o ramp
 
  • #4
What immediately occurs to me is that the ground (where the skateboarder touches down) is at a different height to the end of the ramp (where ballistic motion starts).
The 7.9m/s is at the bottom of the ramp, not the top.
 
  • #5
Yeah that was it the 7.9 was at the bottom of the ramp not the end of the ramp thanks
 

Related to Projectile Motion: Skateboarder on a Ramp

1. What is projectile motion off a ramp?

Projectile motion off a ramp is the motion of an object that is launched from a ramp at an angle to the horizontal. The object follows a curved path due to the combination of its horizontal and vertical velocities.

2. What are the factors that affect projectile motion off a ramp?

The factors that affect projectile motion off a ramp include the angle of the ramp, the initial velocity of the object, the mass of the object, and the force of gravity. These factors determine the path, distance, and time of the object's motion.

3. What is the difference between projectile motion off a ramp and free fall?

The main difference between projectile motion off a ramp and free fall is the initial horizontal velocity. In free fall, the object has no initial horizontal velocity, while in projectile motion off a ramp, the object has an initial horizontal velocity due to the ramp's angle.

4. How does the angle of the ramp affect projectile motion?

The angle of the ramp affects projectile motion by determining the initial horizontal velocity and the height of the ramp. A steeper ramp will result in a higher initial horizontal velocity and a longer horizontal distance traveled, while a shallower ramp will result in a lower initial horizontal velocity and a shorter horizontal distance traveled.

5. Can the mass of the object affect projectile motion off a ramp?

Yes, the mass of the object can affect projectile motion off a ramp. A heavier object will have a greater force of gravity acting on it, causing it to follow a shorter and steeper path compared to a lighter object with a smaller force of gravity. However, the mass does not affect the time of flight or the horizontal distance traveled.

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