Linear motion: Levers: impulse Flashcards
What is linear motion?
Motion in a straight line where all body parts are moving at the same speed.
What is mass?
how heavy something is
how do we measure mass?
kg
what is weight?
gravitational force exerted on an object
how do we measure weight?
N (newtons)
How do we calculate weight?
weight = mass x effect felt by gravity (9.8)
What is inertia?
The reluctance of a body to move.
how do different masses effect inertia?
bigger mass = bigger inertia
smaller mass = smaller inertia
What is distance?
the path a body takes as it moves from the starting point to finishing point.
What is displacement?
The shortest route in a straight line between the start point and an end point
what is speed?
how fast a body’s movement is with no reference to direction
how do we calculate speed?
speed = distance / time
what is velocity?
the rate of change of displacement
how do we calculate velocity?
velocity = displacement / time
What is acceleration?
rate of change of velocity
how do we calculate acceleration?
acceleration = change in velocity / time
How do we calculate momentum?
momentum = mass x velocity
how do we measure momentum?
kgm/s
How do we measure change in velocity?
final velocity - initial velocity / time
what should a net impulse graph look like at the start of a race/take off?
Large positive impulse
what should a net impulse graph look like during the middle of a race?
- equal sized positive and negative impulses
- shows constant velocity
what should a net impulse graph look like at the end of a race?
large negative impulse
what does a first class lever look like?
effort———-fulcrum———-resistance
benefits/disadvantages of first class lever
- large range of motion
- resistance can move quickly
- cannot apply much force to move an object
What does a second class lever look like?
fulcrum———-resistance———-effort
what are the benefits/disadvantages of second class levers?
- can generate much larger forces
- has to lift whole body weight
- slow
- limited range of motion
what does a third class lever look like
fulcrum———-effort———-resistance
advantages/disadvantages of third class lever
- large range of motion
- resistance is able to be moved quickly
- cannot apply much force to move the object
what is a mechanical advantage?
- when the effort arm is longer than the resistance arm
- allows for a larger load to be moved over a small distance with less effort
what is a mechanical disadvantage?
- when the resistance arm is longer than the effort arm.
- means that cannot move as heavy a load but can do it faster.
example of a first class lever
extension of the elbow (triceps)
example of a second class lever
plantarflexion in the ankle
example of a third class lever
- hip flexion
- elbow extension (bicep)
- knee flexion
what is impulse?
The measure of force applied to something over a period of time.
How do we measure impulse?
Ns (Newton seconds)
