Forces and their interactions Flashcards
1
Q
What is a scalar quantity?
A
- only have a magnitude
2
Q
What is a vector quantity?
A
- have a magnitude and and a direction
3
Q
What is magnitude?
A
- a value for size
4
Q
What does the arrow represent for vector quantities?
A
- size of arrow determines magnitude
- direction of arrow determines direction of the vector
5
Q
What are some examples of scalar quantities?
A
- mass
- speed
- distance
- energy
- temperature
6
Q
What are some examples of vector quantities?
A
- force
- velocity
- displacement
- acceleration
- momentum
7
Q
What is a contact force?
A
- when objects are touching
8
Q
What is a non-contact force?
A
- when objects are not touching or are separated
9
Q
What are some examples of non contact forces?
A
- gravitational force
- magnetic force
- electromagnetic force
10
Q
What are some examples of contact forces?
A
- air resistance
- normal contact force
- friction
- tension
11
Q
What is a normal contact force?
A
- force at right angles to the surface
- eg. weight of book balanced by reaction force from the table
“normal” = at 90 degrees
12
Q
How do you calculate weight?
A
w = m x g
weight = N
mass = kg
g = N/kg
13
Q
How do you measure forces?
A
- using a newtonmeter
- calibrated spring balance (spring stretches fixed distance for each newton)
- weight of object considered to act at a single point known as centre of mass
14
Q
What is the gravitational field strength on earth?
A
9.8 N/kg
15
Q
What is a resultant force?
A
- single force that has same effects as many different forces acting together
