Movement, Forces and Shape Flashcards
In the distance-time graph what tells us the speed of the car?
Gradient
Vector quantities are? Examples?
Those that have magnitude and direction. Eg. force, acceleration, weight.
SUVAT Equations of Motion
The formula of acceleration (m/s^2)?
v = u + at v^2 = u^2 + 2as s = ut + 1/2 at^2 s = 1/2 (u^2 + v) t a = (v - u)/t
How to calculate distance from a velocity-time graph?
The area under the graph
Purpose of air-track in an experiment to measure acceleration?
To reduce friction as the glider rides on a cushion of air
What is the normal reaction force?
The force that acts at 90⁰ (example on a car from the ground)
Purpose of increasing and decreasing friction?
Increasing: so cars have a better grip on roads and to make brakes more effective.
Decreasing: to make machines efficient and prevent them from rapid wearing
How to reduce friction in fluids (drag)?
Streamlined, smooth body shape
Safety apparatus for heavyweights?
Catch box with bubble wrap
Hooke’s Law?
“Within elastic limit, force is proportional to the extension”
Elastic Limit
- Upto a certain extension, a spring behaves elastically
- If this critical extension is exceeded (elastic limit) the spring will be permanently stretched
- Hooke’s law is no longer obeyed
Apparatus for finding speed?
Light gates and data logger
Rapid deceleration causes…
accidents
Breaks increase…
friction between the tyres and road
but if applied too hard it can result in skidding
Factors affecting stopping distance?
- Reaction time of the driver
- Speed of the car
- The mass of the contents of the vehicle
- The condition of the road
- The condition of the tyre
s - If tyres have a good tread and are properly inflated
