G7 Forces and energy KA Flashcards
The force of gravity is pulling it toward the center of the earth.
what is this?
Weight
A rock does not move toward the center of the Earth because the ground is pushing up on the rock.
What is this called?
Contact force
What is balanced forces
the forces are equal in size and opposite in directions
Imagine the wind is blowing on a rock and it blows it from one side
why does the rock not move sideways
the pushing force from the wind is balanced by the friction between the rock and the ground
the tennis ball will change direction becuse of an unbalanced force when the ball contacts the tennis racket the ball pushes on the tennis racket to make the ball go back in the opposite direction
the hitting force must be larger that the force from the ball
when forces are equal in size and opposite in direction
the forces are balanced
balanced forces cause no change in
movement
when forces are not the same size or opposite
the forces are unbalanced
unbalanced forces can cause change in movement like
speeding up,slowing down or changing direction
can there be forcese acting on an object even when it is not moveing
yes
what is the standard unit for speed
meters per second
m/s
speed=
distance /time
the formula triangle for speed
speed=distance/time
time=distance/speed
distance=speed x time
An aeroplane travels 2500km in a time of 5 hours what is the speed of the airplane in km/h
=2500km/5hours
=500km/h
Graphs are more useful than words becuse
it is easier to see patterns
you can read any value of distance or time
values like speed can be calculated from the graf
the whole journey can be seen easily
