# Down Hill Crash and slide investigations

## Focus Questions

• How far can the car push a bale of different weight?
• Can the car crash into a bale and not move the bale?
• What is the least amount that the bale will move?
• How does adding weight (washers) to the bale change the distance it will slide when it is hit by the car?
• How does changing the angle change how far it will slide?
• How doe adding weight to the car change the distance the bale will slide?

## Procedure

The K'Nex® DownHill Thrill layout was used (pictures in album below). The end of one of the plastic bales was cut off so that washers could be put inside. The bale was placed at the of the first dip. The first runs pushed the bale up the jump and across the tile floor. Later runs didn't.

• Modified the plastic hay bale (cut the topoff so we could insert washers) and placed it at the bottom of the hill at the point where two tracks met.
• Placed a ruler beside the track to measure the distance the bale slide.
• Longer slides slid up the hill and across the floor until the bale came to a rest.
• Longer slides were easier to measure.
• As more washers were added the bale would slide up the hill stop and slide back down.
• An observer positioned at the bottom of the track watched carefully to see how far the bale slide before it rolled back.
• Three trials were made and recorded in a spreadsheet and graphed with the software.

Learners who participated were a mixed age group from 10-12 years old.

## Three sets of data and graphs

### Set 1 Chart and Graph of Down Hill Crash

Car rolls down ramp and crashes into the bale with different mass (number of washers).

Bale slides on ceramic tile.

Number of washers in bale
Distance bale slid on tile
0 1 2 3 4 5 6 7 8 9 10 11 12 13
Trial 1 66 41 32 25 28 24 31 20 14 15 13
Trial 2 72 79 56 45 30 35 30 78 21 15 13 65 7 17
Trial 3 100 80 74 33 42 44 41 25 17 15 19 9 9 8
Mean 79 67 54 34 33 34 34 41 17 15 15 37 8 13

### Set 2 Chart and Graph of Down Hill Crash

Car rolls down ramp and crashes into the bale with different mass (number of washers).

Bale slides up jump ramp - Layne

Number of washers 0 1 2 3 4 5 6 7 8 9 10 11 12
Trial 1 51 36 10 7 6 4 1 3 2 1 2 1 1
Trial 2 65 41 8 7 5 5 2 3 2 2 3 2 2
Trial 3 56 42 9 6 6 5 3 3 2 2 4 3 3
Mean 57 40 9 6.7 5.7 4.7 2 3 2 1.7 3 2 2

### Set 3 Chart and Graph of Down Hill Crash

Car rolls down ramp and crashes into the bale with different mass (number of washers).

Bale slides on carpet.

Number of washers in bale
Distance Bale Slid in inches
0 1 2 3 4 5 6 7 8 9 10 11
Trial 1 49 23 11 8 7 5 4.5 4.3 4.5 4 3.5 4.5