# Skateboarding Down a Ramp: Finding Speed at Bottom

• sallychan
In summary, a student is skateboarding down a 5.9 m ramp inclined at 12° with an initial speed of 2.3 m/s. Neglecting friction, the speed at the bottom of the ramp can be found using the equations of motion. However, as the weight of the student is unknown, other methods such as conservation of energy or rotating the coordinate axes may be used to find the final speed.

## Homework Statement

A student is skateboarding down a ramp that is 5.9 m long and inclined at 12° with respect to the horizontal. The initial speed of the skateboarder at the top of the ramp is 2.3 m/s. Neglect friction and find the speed at the bottom of the ramp.

## Homework Equations

This is my steps:
As I don't know the weight of the student, I don't know the force. So I can't use F-ma

Vo=2.3
Vox= 2.3cos78°= 0.48
Voy= 2.3sin78°=2.25
t=0.32

ΔY (found by SOPHATOA) =Voy.t+1/2 a t^2
1.23= 2.25t+1/2(9.8) t^2

ΔX=Vox.t+1/2 a t^2
5.8=0.48(0.32)+1/2.a.(0.32)
ax=110.3

Vx=Vox+at
Vx=0.48+110.3(0.32)
Vx=35.8

Vy=Voy+at
Vy=2.25+9.8(0.32)
Vy=5.386

therefore the resultant of Vx and Vy is 36.2

## The Attempt at a Solution

I really need some help :D

Mg is counter-acted by normal force...
For easier methods:
You could just use conservation of energy.
Or you could rotate the coordinate axes.(x-axis along the ramp, y perpendicular)

## 1. How does a skateboarder gain speed while going down a ramp?

The speed of a skateboarder going down a ramp is determined by a combination of factors, including the angle of the ramp, the mass of the skateboarder and their board, and the force of gravity. As the skateboarder descends down the ramp, their potential energy is converted into kinetic energy, causing them to gain speed.

## 2. Does the shape or material of the ramp affect speed?

Yes, the shape and material of the ramp can affect the speed of a skateboarder. A steeper ramp will result in a faster descent and a smoother surface will allow for less friction and therefore, more speed. Additionally, the shape of the ramp can influence the direction and trajectory of the skateboarder, affecting their overall speed.

## 3. How can a skateboarder maintain control and balance while going down a ramp?

Skateboarders maintain control and balance while going down a ramp by using their body's center of mass and shifting their weight accordingly. They also use their feet to steer and adjust their speed by applying pressure to the board. Practice and proper technique are essential for maintaining control and balance while skateboarding down a ramp.

## 4. Is it possible to go faster by pumping on a ramp?

Yes, pumping on a ramp is a technique used by skateboarders to gain speed without the use of their feet. By compressing and extending their legs in a rhythmic motion, skateboarders can generate additional speed while going down a ramp. This technique requires practice and proper timing to be effective.

## 5. What are some safety precautions for skateboarding down a ramp?

Skateboarding down a ramp can be dangerous, so it is important to take proper safety precautions. This includes wearing a helmet, elbow and knee pads, and closed-toe shoes. It is also essential to thoroughly check the ramp for any potential hazards before using it and to always start with a small ramp and gradually work your way up to larger ones. Proper supervision and learning proper skateboarding techniques are also important for safety.