Topic 5 - Forces (2)

Question 1

RESULTANT FORCES AND WORK DONE:
What do free body diagrams show?

Answer 1

all the forces acting on an object or system but none of the forces the object or system exerts on the rest of the world

Question 2

RESULTANT FORCES AND WORK DONE:
What do the arrows on free body diagrams show?

Answer 2

• the sizes of the arrows show the relative magnitudes of the forces
• the directions show the directions of the forces acting on the

Question 3

RESULTANT FORCES AND WORK DONE:
What is a resultant force?

Answer 3

the overall force on a point or object

Question 4

RESULTANT FORCES AND WORK DONE:
How can you calculate the resultant force on an object?

Answer 4

adding forces going in the same direction nd subracting any going in the opposite direction

Question 5

WEIGHT, MASS AND GRAVITY:
What is gravitational force?

Answer 5

the force of attraction between masses

Question 6

WEIGHT, MASS AND GRAVITY:
What are the two main effects of gravity?

Answer 6

1) on the surface of a planet, it makes all things fall toward the ground
2) it gives everything a weight

Question 7

FORCES AND ELASTICITY:
What 3 thing may happen yo an object when you apply a force too it?

Answer 7

it could,
stretch
compress
or bend

Question 8

FORCES AND ELASTICITY:
Why do you need more than one force acting on an object to make it stretch, compress or bend?

Answer 8

if only one force was acting on the object the objects would simple move in the direction of the applies force

Question 9

FORCES AND ELASTICITY:
What does it man if an object has been elastically deformed?

Answer 9

it can go back to its original shape and length after the force had been removed

Question 10

FORCES AND ELASTICITY:
What os the name for objects that have been elastically deformed?
Give an example?

Answer 10

they are called elastic objects
(e.g. a spring)

Question 11

FORCES AND ELASTICITY:
What does it mean if an object has been inelastically deformed?

Answer 11

it doesn’t return to its original shape and length after the force has been removed

Question 12

FORCES AND ELASTICITY:
How is energy transferred when an object is stretched or compressed?

Answer 12

work is done when a force stretches or compresses an objects causing energy to be transferred to the elastic potential energy store of the object

Question 13

FORCES AND ELASTICITY:
What store is energy transferred to in elastically deformed objects?

Answer 13

all the energy is transferred to the object’s elastic potential energy store

Question 14

FORCES AND ELASTICITY:
When a spring (or other elastic object) is supported at the top, what is the relationship between the load (force applied) and the extension of the spring?

Answer 14

they are directly proportional

Question 15

FORCES AND ELASTICITY:
What does the spring constant depend on?

Answer 15

the material that you are stretching

Question 16

FORCES AND ELASTICITY:
What springs have greater spring constants?

Answer 16

a stiffer spring has a greater spring consant

Question 17

FORCES AND ELASTICITY:
REMEMBER: There is a limit to the amount of force you can apply to an object for the force to keep on increasing proportionally