Contact and non contact forces

Question 1

What do vector quantities have? What’s an example of a vector?

Answer 1

• they have magnitude and direction
  force, velocity, displacement, acceleration and momentum

Question 2

What do scalar quantities have? What’s an example of a scalar?

Answer 2

• only have magnitude but no direction.
  -speed, distance, mass, temp and time

Question 3

Define force , non contact and contact

Answer 3

• A force is a push or pull on an object that is caused by it interacting with something, all forces are either contact or non contact
• Contact force = 2 objects must be touching for a force to act
• Non-contact force = 2 objects don’t need to be touching for a force to act

Question 4

When —- objects —–,there is a —– produced on —— objects
Define interaction pair

Answer 4

• 2,interact,force,both
  -Its a pair of forces that are equal and opposite and act on two interacting objects

Question 5

Gravity attracts —– —— but when do you only notice it?

Answer 5

all masses
but you only notice it if one of the masses is really big for example = planet

Question 6

2 important effects of gravity

Answer 6

• On the surface of a planet, it makes all things fall towards the ground
  -it gives everything a weight
  -

Question 7

Define Mass

Answer 7

• the ‘amount of stuff’ in an object, for any given object this will have the same value anywhere in the universe

Question 8

Define weight

Answer 8

• Its the force acting on an object due to gravity close to earth, this force is caused by the gravitational field around the earth

Question 9

What does the weight of an object depend on?

Answer 9

• gfs varies with location. its stronger the closer you are to the mass causing the field, and stronger for larger masses
• The weight of an object depends on the strength of the gravitational field at the location of an object. This means weight changes with location.
• For example an object will have the same mass whether its on earth or mars but it will have a different weight simply due to the gfs which is less on the surface of the moon

Question 10

What is weight(force) measured in?
How is weight measured?

Answer 10

Weight is a force which is measured in newtons with a centre of mass.
- measured using a calibrated spring balance or newtonmeter

Question 11

What is Mass(not a force) measured in?
How is mass measured?

Answer 11

• Mass is not a force and is measured in kg with a mass balance

Question 12

EQUATION FOR WEIGHT

Answer 12

Weight (N) = mass (kg) x gfs (N/kg)

Question 13

gfs for earth and moon

Answer 13

• 9.8n/kg
• 1.6n/kg

Question 14

increasing —– of an object —— its ——
Why?

Answer 14

mass, increases, weight
weight and mass are directionally proportional