# Using physics to make things work

HideShow resource information
• Created by: KAustria
• Created on: 18-05-14 07:19
What is a moment?
The turning effect of a force.
1 of 31
How can you calculate moment?
Moment ( Nm) = Force (N) x Perpendicular line of action to the pivot (m
2 of 31
How do you increase the moment?
1. Increase the force 2. Increase the distance tot he pivot
3 of 31
When using a lever, what is the load and effort?
When using a lever, the force are trying to move is called effort and the force applied to the lever is called effort.
4 of 31
What is a force multiplier?
The effort we can apply to the lever is much less to the load we are trying to move.
5 of 31
what is the centre of mass?
The mass of an object is thought to be ceoncentrated to one single point.
6 of 31
What happens to the centre of mass of an object in equilibrium?
1. The centre of mass is directly below the point of suspension.
7 of 31
Where is the centre of mass of a symmetrical object?
1. Along the axis of symmetry 2. if more than one axis, it where the axes of symmetry meet.
8 of 31
What is happening to an object that is in equilibrium?
It is balanced, not turning because the total clockwise moment and the total anticlockwise moment are equal.
9 of 31
How do you calculate the force needed to stop an object from turning?
Sum of anticlockwise moments about any point = the sum of the clockwise moments about that point
10 of 31
How does a line of action work?
The line of action of the weight of an object acts through its centre of mass.
11 of 31
What causes an object to topple over?
A resultant moment will occur when the line of action lies outsde the base of an object.
12 of 31
How is the stability of an object increased?
1. Wider base 2. lower centre of mass
13 of 31
What is pressure measured in?
Pascals, Pa
14 of 31
What are the features of liquids?
They are virtually incompressible and the pressure in a liquid is transmitted equally in all directions.
15 of 31
If a force is exerted in point in a lqiuid..
The force will transmitted to other points in the lqiuid.
16 of 31
What is a hydraulic system?
Using pressure in a fluid to exert a force.
17 of 31
The force exerted by a hydraulic pressure system depends on what?
1. the force exerted 2. The area of the cylinder on which forces act on 3. The area of the cylinder hat exerts the force.
18 of 31
How can an hydraulic system be used as a force multiplier?
The different cross-sectional areas on the effort and load side of an hydraulic system.
19 of 31
Define centripetal acceleration
The acceleration towards the centre of the circle of an object that is moving around the circle.
20 of 31
What is the centripetal force?
The resultant force which causes an object to accelerate, which always acts towards the centre of the circle.
21 of 31
What happens if the centripetal force stops acting?
The object ill continue to move in a straight line tangent to the circle.
22 of 31
What are the 3 main factors which increases the centripetal force to make an object perform circular motion?
1. The mass increases 2. The speed increases 3. The radius decreases.
23 of 31
What is oscillating motion and give an example?
When an object , like a pendulum, moves to and fro along the same line.
24 of 31
What does a cimple pendulum consist of?
A bob ( mass) suspended on string.
25 of 31
What is the euilibrium poisition?
The position of the pendulum where it stops moving.
26 of 31
What is the amplitude in a oscillation?
The distance from the equiliprium position to the highest point.
27 of 31
What is the time period of an oscillation?
1, Time taken form one high point ot another 2. time is taken between successive passes in the same direction through the equilibrium position.
28 of 31
How can you measure the ime period simply?
The avg time it takes for 20 oscillation and divide the timing by 20
29 of 31
What does time period depend on?
1. Length of pendulum - this increases and length increases
30 of 31
What is the frequency in an oscillation?
the number of complete cycles of oscillations per second.
31 of 31

## Other cards in this set

### Card 2

#### Front

How can you calculate moment?

#### Back

Moment ( Nm) = Force (N) x Perpendicular line of action to the pivot (m

### Card 3

#### Front

How do you increase the moment?

### Card 4

#### Front

When using a lever, what is the load and effort?

### Card 5

#### Front

What is a force multiplier?