Investigating the relationship of projectile range and projectile motion using a ski jump.

Introduction

As we all know ski jumping is a worldwide sport in which athletes skate down a slope ramp, gaining speed that throws them in the air that makes them land some distance away. The distance travelled at the time when the jumper leaves the ramp, until he reaches the ground is known as the jump range. This interesting and challenging sport involves a lot of physics behind it. Kinetic energy, gravitational potential energy, motion, speed, height, time, distance and the athlete's ability to reduce air resistance to their body are all factors that determine the athlete's performance. This experiment represents a ski jumping slope through which we will investigate and demonstrate how physics can be used by ski jumpers to increase their range in the jump.

Aim:  My aim of this experiment is to explore the relationship between the launch height and the range of the jump. I will use the my knowledge of physics knowing that gravitational potential energy can be converted into kinetic energy and using the equations ∆Egrav = mg∆h for gravitational potential energy and Ek = ½ mv2for the kinetic energy to work out the relationship between height, velocity and the range of the projectile.

Hypothesis

Procedure

1. Set up the apparatus shown in the diagram using the clamp stand boss and clamp, and the plastic ramp on top of a table.
2. Place the carbon paper on the floor, placing 4 x A3 sheets of plain paper underneath the carbon paper.
3. Make sure that the top of the ramp curves downwards towards the edge of the table, so the end of the ramp meets the edge of the table.
4. Weigh the ball baring using the weighing scales (in Newtons) and note down the weight.
5. Make sure that the ramp is secure, use masking tape if needed and measured accurately using the meter ruler. The height (h1) is 30 cm from the table to the point of drop – this will be the starting height.
6. Position the ball baring on the ramp where the bottom of the ball baring touches the 30 cm point. Steady the ball with your finger until release.
7. Once ready, release the ball baring down the ramp, making sure that it hits the carbon paper. Repeat this 3 times. Measure the range from the furthest point of contact on the paper to the edge of the table.

In this investigation, I have taken account of h1 as my variable and all other factors are being fixed and so remain constant. I can also investigate h2 if I will do this experiment again. It is different from h1 because the ramp will always be in a fixed position and so the angle of the ramp will not change. So, the initial velocity will always be the same.

Conclusion

The conclusion to this experiment is that as the vertical projecting height increases, the horizontal distance travelled also increases. However, it is the air resistance and fiction of the ramp that limits the projectile motion. From my results, it shows that air resistance has little effect on the ball baring if the time spent in the air is less, when h1 is at a low height. However, if the ball baring travels in the air for longer, when h1 is at a higher level, the affect of air resistance is applied for longer when the projectile leaves the ramp and affects the horizontal distance travelled. From my results, I can conclude that my investigation supports my hypothesis and disproves my null hypothesis. However, this also proves that air resistance and friction is a big limiting factor.