Forces

Question 1

What is a vector?

Answer 1

requires both magnitude and direction

Question 2

What is a scalar?

Answer 2

requires only magnitude

Question 3

Describe what a contact-force is? Give me 2 examples

Answer 3

A force which acts on an object coming physically in contact. E.g. push or pull force

Question 4

Describe what a non-contact force is? Give 2 examples

Answer 4

A force which acts on an object without coming physically in contact with it. e.g. gravity, magnetic

Question 5

Name some examples which contain scalar quantities

Answer 5

• speed
• time
• temperature
• distance
• density
• energy

Question 6

Name some examples which contain vector quantities

Answer 6

• velocity
• acceleration
• displacement
• forces
• magnetic induction

Question 7

What is the resultant force?

Answer 7

the overall force acting on an object

Question 8

How can we work out what the resultant force is?

Answer 8

• Opposite forces cancel each other out
• what’s left is the resultant force

Question 9

What is the term used to describe when all the forces are balanced?

Answer 9

at equilibrium

Question 10

Name 3 things that springs can do

Answer 10

compress
stretch
bend

Question 11

Describe the term elastic deformation

Answer 11

when all forces are removed from the object, but it goes back to its original shape

Question 12

Describe the term inelastic deformation

Answer 12

when all forces are removed from the object, but the object doesn’t return to its original shape, they have met the limit of proportionality

Question 13

What is the extension of the spring?

Answer 13

increase in length of a spring when it’s stretched

Question 14

What happens to the spring when more mass is added to it?

Answer 14

• higher spring constant - stiffer material
• as force increases, extension increases

Question 15

State Hooke’s Law

Answer 15

force and extension are directly proportional

Question 16

What do we mean when we say the spring has a low or high spring constant?

Answer 16

Lower spring constant - easier to stretch
Higher spring constant - harder to stretch

Question 17

Describe the term moment

Answer 17

the rotational or turning effect of a force

Question 18

What happens to the output force and the input force if they are each on different sides of the pivot to one another?

Answer 18

they act in different directions

Question 19

What happens to the output and input force when they are both on the same side of the pivot?

Answer 19

they act in the same direction

Question 20

What is pressure?

Answer 20

force per unit of area

Question 21

What is a perpendicular force?

Answer 21

component of the force which is at right angles to the surface its colliding with

Question 22

Describe the pressure in liquids

Answer 22

-pressure due to the weight increases as blocks submerges further into the water
- the denser the liquid, the larger the mass per volume, meaning a larger weight