Motion
speed
time graphs
Acceleration
flat lines mean the object is stationary
stopping distances
Momentum
Speed is a measure of how fast an object is moving.
Stopping Distance is the time it takes to stop from a certain speed to 0 while moving
Speed is stated as a length per unit of time. For example a speed could be 70 miles per hour, while another speed could be 45 metres per second.
Calculate speed using the speed equation - speed = distance divided by time. The speed equation can be rearranged to find distance travelled and time taken.
up means the object is taveling away from the place
The steeper the slope the faster the speed
vice verca
to figure out the force of something, you need to times the mass by the acceleration
to find out mass, you need to divide force by acceleration
Acceleration is the increase of somethings speed or rate
to find out acceleration, you need to divide the change in speed by time.
Drag Forces and friction
Drag Forces
Friction
Ways to reduce it
Lubrication is where oil or grease are put on object to make it slippery/ less friction
Drag forces are like friction types, eg, water, air and other elemental resistances reduce speed to varying degrees
Friction is where particles are in the way of others, the blocked particles use some energy to either move past or push the blocking particle out of the way
For example an elephant has no momentum when it is standing still. When it begins to walk it will have momentum in the same direction as t is travelling. The faster the elephant walks the larger the momentum will be
Momentum is the product of mass and velocity. momentum is also a vector quality - this means it has both a magnitude and a direction.
calculations
stopping distance
force
Momentum
mass x velocity
p =mv
Mass (m) is measured in kilograms (kg)
Velocity V is measured in metres per second (m/s)
Momentum (p) is measured in kilogram metres per second (kgm/s).
thinking distance + braking distance.
mass x acceleration
friction
coefficient of friction x normal force
speed
distance travelled / time taken
Thinking distance and Breaking Distance
Thinking Distance between seeing something and then doing something to slow down
Braking Distanceis the time it takes for the slowing factor to slow you down until stopping