Linear Motion and suvat equations Flashcards
What do all the letters in suvat stand for?
s = displacement (m) u = inital velocity (ms^-1) v = final velocity (ms^-1) a = accleration (ms^-2) t = time (s)
When do you use suvat?
When there is constant acceleration.
How do we derive the suvat equations?
Using the Equations of motion graph.
Sketch the equation of motion graph?
Look at notes!
A mug is dropped from 2.0m. How long does it take to hit the ground and how fast does it hit the ground?
t = 0.639s. v = 6.26ms^-1.
What value is g?
9.81ms^-2.
What does stopping distance equal?
Thinking distance + Braking distance.
What depends on someone’s thinking distance? (5)
1) The speed you are traveling
2) tiredness
3) Drugs
4) Alcohol
5) Distractions
What depends on someone’s braking distance? (4)
1) Their speed
2) The condition of their brakes
3) The condition of their tires
4) The road surface
What is reaction time directly proportional to?
The distance traveled.
What is the distance traveled proportional to?
The (initial speed)^2.
How is the distance traveled directly proportional to (initial speed)^2? (3)
1) Due to W=fx
2) Ek = 1/2mu^2
3) fx = 1/2mu^2
The smaller the reaction time the smaller the………
Thinking distance.
What should you remember when calculating the braking distance from a speed-time graph?
You are calculating the area under the graph from the point when the brakes are applied.
Describe a practicle to determine g. (3)
1) Set up the experiment with three clamp stand and one tripod as shown in the diagram with an electromagnet placed at the top connected to the metal ball. You should have an upper light gate and the lower light gate which are connected to a stopwatch.
2) When the electromagnet is turned off, the metal ball becomes detached from the electromagnet and accelerates through the top light gate and starts the timer then the timer is stopped as it passer throughout the lower light gate. Remember to have soft padding at the bottom to prevent damage to the object or table.
3) Plot a graph of 2s against t graph where you should expect a straight line with the gradient being equal to a.
What has to be kept constant during the practice for determining g?
The distance between the object on the electromagnet to the upper light gate.
Draw a diagram for the practice to determine g.
Look at notes.
How do you know 2s/t = a = gradient?
Because:
1) s=ut+1/2at^2
2) 2s=2ut+at^2
3) 2s/t=2u+at
y =c +mxWhat is the acceleration independent of?
The mass of the object.
Why is the coins maimum height, when flipped into the air, zero?
Because for a fraction of a second the coin stops moving to then fall back down.
Define thinking distance.
Distance travelled between when the driver sees a problem and the time at which the brakes are applied.Thinking distance = speed x reaction time. Where reaction time is dependent on tiredness, alcohol or drug use, illness and distractions.
Define braking distance.
The distance travelled from when a driver applies the brakes until the vehicle stops. It is affected by the road conditions and the quality/wear of the tyres.
Define stopping distance.
The distance travelled from the driver seeing a problem to the vehicle coming to a complete stop.Stopping distance = Thinking distance + Braking distance.
Define reaction time.
The time taken between a driver seeing a problem and reacting to the problem (i.e. applying the brakes).
What is thinking distance directly proportional to?
The inital speed.
What is braking distance directly proportional to?
The (speed)^2.
