- #1

Liam C

- 57

- 4

## Homework Statement

Nikhil is probably eating his daily snack at this time. Old Man Miller comes back from the store and takes the 0.150kg sandwich from Nikhil as he begins to run away. Nikhil is running at 7.5m/s away from me when I hit him in the head with the sandwich that was moving at 17.5m/s when it makes contact with the back of his head. Determine the average force the sandwich applies to Nikhil's head if it is in contact with his head for a period of time which allows the sandwich to move 15cm forward before it falls to the ground.

## Homework Equations

Where t is time:

t = Δd / (v1 + v2 / 2)

Where Vav is the average velocity:

Vav = Δd / Δt

Where Fav is the average force:

Fav = m × Vav / t

## The Attempt at a Solution

m = 0.150kg

Δd = 15 cm = 0.15m

v1 = 17.5m/s

v2 = 0m/s

t = ?

Fav = ?

t = 0.15 / (17.5 / 2)

t = 0.017s

Vav = 0.15 / 0.017

Vav = 8.82m/s

Fav = (0.150)(8.82) / 0.017

Fav = 79N

∴ The average force applied to Nikhil's head by the sandwich is 79N

I was never taught average force in class so if my understanding is incorrect that is why. That is also why I am not confident in my answer and need help. Is my method correct, and if not where did I go wrong?