P5 - Forces Flashcards
What is a force?
A push or a pull on an object caused by its interaction with something.
What are the two types of forces?
Contact forces and non-contact forces.
What is a contact force?
A force that acts when two objects are touching.
Give examples of contact forces.
- Friction
- Air resistance
- Tension in ropes
- Normal contact force
What is a non-contact force?
A force that acts when objects do not need to be touching.
Give examples of non-contact forces.
- Magnetic force
- Gravitational force
- Electrostatic force
What is the definition of a vector quantity?
A quantity that has both magnitude and direction.
Is force a vector or scalar quantity?
Vector quantity.
List some examples of vector quantities.
- Force
- Velocity
- Displacement
- Acceleration
- Momentum
What is a scalar quantity?
A quantity that has magnitude but no direction.
List some examples of scalar quantities.
- Speed
- Distance
- Mass
- Temperature
- Time
What does Newton’s Third Law state?
For every action, there is an equal and opposite reaction.
What force attracts the Sun and the Earth to each other?
Gravitational force.
Describe the normal contact force in relation to a chair and the ground.
A chair exerts a force on the ground, while the ground pushes back at the chair with the same force.
What is Gravitational Force?
The Force of Attraction Between Masses
Gravitational force causes objects to be attracted to planets or stars.
What is the difference between mass and weight?
- Mass is the amount of ‘stuff’ in an object
- Weight is the force acting on an object due to gravity
How does gravitational field strength vary?
It varies with location and is stronger closer to the mass causing the field and for larger masses.
Does the weight of an object change with location?
Yes, the weight of an object depends on the strength of the gravitational field at its location.
What is the weight of a 1 kg mass on Earth?
About 9.8 N
What is weight measured in?
Newtons
What is the formula for calculating weight?
Weight (N) = Mass (kg) x Gravitational Field Strength (N/kg)
What is the approximate value of gravitational field strength (g) on Earth?
9.8 N/kg
What is the approximate value of gravitational field strength (g) on the Moon?
1.6 N/kg
Are mass and weight directly proportional?
Yes, increasing the mass of an object increases its weight.