Forces Flashcards
What are the 3 contact forces?
- Friction
- Air resistance
- Tension
What are the 3 non-contact forces?
- Weight
- Magnetic force
- Electrostatic force
State 2 ways friction is useful in daily lives.
Walking, writing on paper, lighting a fire, parachuting.
State 2 ways friction is a nuisance in daily lives.
Wear and tear of moving parts, reduces efficiency in machines, reduces speed.
What are 2 ways to reduce friction?
Attach wheels to the bottom of an object, use lubricant or polishing the surfaces.
What is the definition of non-contact force
A force that acts on an object without touching it.
What is the definition of mass?
Amount of matter in a body.
What is the definition of weight?
Force of gravity acting on a body.
What is the SI unit of mass and weight?
Mass: Kilogram
Weight: Newton
What is used to measure mass?
Beam/electronic balance
What is used to measure weight?
Spring balance
Which, mass or weight, is dependant on location (gravitational field strength)?
Weight.
What is the formula for weight?
Weight = Mass × gravitational field strength
State two uses of forces in daily lives.
Opening a door, pressing a button in a lift, squeezing a tube of toothpaste, turning on a tap.
What are the effects of forces on the shape of an object?
Change in shape and size of an object.
What are 2 effects of forces on the motion of an object?
- Move a stationary object.
- Change direction in which an object is moving.
- Change speed of the moving object.
- Stop a moving object.
What is pressure?
The amount of force exerted per unit area.
What is the formula for pressure?
Pressure = Force ÷ Area
What is the symbol, SI unit and SI unit symbol for pressure?
P, pascal, Pa
State how pressure is used in everyday life.
Using fingers to apply force on the head of a thumbtack to allow the pin to pierce paper and wooden boards.
How do straws work?
By sucking through the straw, we lower the air pressure in the straw. The higher atmospheric pressure outside the straw pushes the liquid up the straw.
