Forces Flashcards
revise
What are the three effects that indicate the presence of a force?
CHANGE SPEED
CHANGE DIRECTION
CHANGE SHAPE
Can you categorise forces into push, pull and turning forces?
PUSHING= hockey stick on the ball
PULLING= tug of war
TURNING= using a spanner
Can you state the three different non-contact forces?
GRAVITATIONAL
MAGNETIC
ELECTRIC
What are non-contact forces also known as?
Force fields
What are force fields?
A region in space within which you can detect a non-contact force.
What is the unit of force?
newton (N)
What is an objects weight?
The force due to gravity pulling it downwards to the centre of Earth.
Which materials will be attracted to a magnet?
Any metal that has IRON in it and some NICKEL or COBALT
Can you see a force?
NO, you can observe the effects of a force.
Out of:
0-1N
0-25N
0-50N
What is the strongest spring?
0-50N, because it has to support the greatest force.
Can you draw a diagram annotated about a newton balance
SEE FLASHCARD
Explain the function of a newton balance.
-to measure forces
-push or pull forces
What do unbalanced forces do?
Make things accelerate
What do balanced forces?
-to stay at rest
-move with a constant speed in a straight line
What is mass?
The amount of matter an object has. The mass of an object remains the same everywhere.
What is mass measured in?
KILOGRAMS (KG)
What is weight?
The force of gravity pulling down an object. Weight of an object depends on M and G.
What is weight measured in?
NEWTONS (N)
What is the calculation using the 5,2,10 formula?
W=MG
Weight = mass x gravitational field strength
e.g-
10 = 5x2
5 = 10/2
What does a newton balance tell you about gravitational field strength?
It tells you the gravitational force on a 1kg mass.
What is the unit for gravitational field strength?
Newtons Per Kilogram
(N/kg)
What is the gravitational field strength near Earth?
10 newtons per kilogram
g = 10N/kg
How much will a 1kg mass weigh in Newtons on Earth?
10N
What will be the weight of a 5kg mass near the Earth’s Surface?
W=MG
W=?
M= 5 kg
G=10N/kg
= 5x10
=50N
W=50N
Does gravitational force stay the same in different locations?
G has different values when in outer space or near a planet other than Earth.
What is friction?
A force acting between two surfaces in contact and opposite to their relative movement.
What is a NORMAL REACTION?
A force. Normal means at right angles
Why do bumpy surfaces not slide over each other easily?
Lots of friction is created.
What are ways of reducing frictional forces?
USE A LUBRICANT
oil or water
USE ROLLERS
WHEELS
AIR CUSHION
What is the relationship between friction and direction of motion?
SEE FLASHCARD DIAGRAM
Friction forces oppose the direction of motion.
Explain how the brakes on a bicycle work.
Friction, they convert kinetic energy into heat.
What are the names for up and down forces?
Weight = DOWN
Normal Reaction Force = UP
Comment on the sizes of the up and down forces.
They’re equal in size and opposite in direction.
What are the names for the backward forces when the car is travelling at a constant speed.
Engine force = LEFT
Friction = RIGHT
What is Newton’s First Law?
That an object at rest or moving with a constant velocity will do so unless acted upon by an unbalanced force.
