Flashcards in Biomechanics class test 2 April Deck (29):

1

## What is the formula for limiting friction?

### Coefficient of limiting friction x perpendicular reaction force

2

## What is the formula for sliding friction?

### Coefficient of sliding friction x perpendicular reaction force

3

## What is the formula for the coefficient of restitution?

### -e= v/u

4

## What is the formula for radians?

### Length of arc/ radius of circle

5

## What is the formula for angular velocity?

### Change in angular displacement/ change in time

6

## What is the formula for angular acceleration?

### Change in angular velocity/ change in time

7

## What is the formula for a torque?

###
Force x perpendicular distance from axis of rotation

Moment of inertia x angular acceleration

8

## What is the formula for moment of inertia?

### Mass x distance from axis of rotation squared

9

## What is the formula for momentum?

### Velocity x mass

10

## What is the formula for angular momentum?

### Moment of inertia x angular velocity

11

## Define friction

### The force that arises when one body moves/ tends to move

12

## What does the coefficient of friction depend on?

### Material and roughness

13

## When an object is static, is the magnitude of friction equal to the force?

### Yes

14

## What does rolling friction depend on?

### Weight, radius, deformability, coefficient

15

## Define elasticity

### Ability of body to return to original shape once deformed

16

## What is the coefficient of restitution?

### A measurement of elasticity

17

## What s an oblique impact?

### When bodies don't collide 'head on'

18

## How can you reduce a force?

### Spread over a longer period of time

19

## Define projectile motion

### Motion of objects under influence of ar resistance and gravity

20

## Do internal forces change motion of centre of gravity?

### No

21

## Then the release height is the same as the landing height, what is the optimal release height?

### 45 degrees

22

## What direction does drag act?

### In direction of air flow

23

## What direction does lift act?

### At right angles to drag

24

## When is an angle formed?

###
2 lines

2 planes

1 line and 1 plane

25

## Is angular displacement vector or scalar?

### Vector

26

## Is angular distance vector or scalar?

### Scalar

27

## Normally, is a clockwise displacement considered positive or negative?

### Negative

28

## What to concentric and eccentric forces cause

###
Concentric- linear

Eccentric- Angular and linear

29