03. Velocity and acceleration
Learning intentions
the difference between speed and velocity
the difference between vectors and scalars
how to calculate the acceleration of an object
the difference between acceleration and deceleration
If a car accelerates from 20m/s to 86m/s in 5.2 seconds, what is its acceleration?
A motorbike takes 2.5 seconds to go from rest to 24 .8 m/s. what is its acceleration?
Danish thrown off the fourth floor reaches 12.6 m/s in 1.3 seconds. What is his acceleration?
A teacher sees a Y10 in the road and decides to stop. It takes their car 2.5 seconds to stop from 15.8 m/s, what is their deceleration?
Investigating Acceleration
Use the ramps and light gates to find out how the slope affects velocity.
Collect reliable results over a suitable range of heights.
From the datalogger menu
Timing
Velocity at A
Measure and enter the length of interrupt card
Choose sensible levels of precision (decimal places)
Press play
Write a conclusion for your results.
Are they reliable?
What is displacement?
Blindfold a partner, place a tennis ball near them.
Tell them the distance it is from them.
Tell them to fetch it.
Why did they struggle?
What do you need to tell them?
Whilst your partner is blindfolded, walk twenty steps from them in various directions and drop the bean bag.
Ask them to find the bean bag.
What do you need to tell them?
THE INFORMATION IS DISPLACEMENT
IT IS AN EXAMPLE OF A VECTOR
SCALAR OR VECTOR
FORCE
SPEED
ACCELERATION
ENERGY
VOLUME
DISTANCE
DISPLACEMENT
TEMPERATURE
TIME
A ships course / BEARING
Have a play with the simulation. What makes the measurements VECTOR quantities.
What does having zero acceleration mean?
Put the man at one end. Set the velocity to go the other way. Predict the time it would take him. Try and see if you are correct.
Speed = Distance/Time
Put the man at one end at a standstill. Set the acceleration to 1m/s2 the other way. Predict the velocity after 2 seconds. Record and Playback.