Acceleration Test
Speed or Velocity: A bike goes 25 m/s toward main street A person walks 4 mph Scalar or Vector: 40 mph toward Dallas A 25 N force pulls on a wagon
V S V S
A person starts running from 2 m/s to 6 m/s in 2 seconds. Calculate the person's acceleration.
Vi = 2 m/s a = ? Vf = 6 m/s t = 2 vf = vi + a(t) 6 = 2 + 2a 4 = 2a 2 = a m/s (6 m/2 * 2 m/s)/2s = 2 m/s^2
d = 1/2at^2
just a note
Units: a s or v m D F T
m/2^2 m/2 kilograms meters newtons sec
m/s / s/1 ->
m/s * 1/s -> m/s^2
With free fall acceleration, what relationship is present with each successive number? Distance between points are _______.
increasing by a square odd
_______ describes an objects speed and direction
velocity
A dragsters top acceleration is 60 m/s^2 If it accelerates for 3 seconds from the starting line, how fast will it be going?
vf = vi + at vf = 0 + 60m/s^2(3s) vf = 180 m/s
The size of an acceleration depends on both the change in velocity and the _______ of the change
time interval
A guy bikes 15 miles in 1 hour, then rest for an hour. Then he bikes 25 in 2 hours. What was his average speed for the trip.
total d = 40m total t = 4 hrs 10 mph
The equation for average acceleration is _______
a = (vf - vi)/f = deltav/t
The rate of change of velocity is called _______
acceleration
The velocity of an object an _______ even if the speed of the object remains constant. This would occur if the ________ of the motion changes.
change direction
To calculate acceleration, _______ the change in velocity by the time interval
divide
Final velocity will be less than initial velocity if an object if an object is _______, and acceleration will have a _______ value. Otherwise, we are ________ and acceleration will be _______, if moving.
slowing down negative increasing speed positive
_______ is the rate of motion of an object
speed
To find the change in velocity, _______ the initial velocity (vi) from the final velocity (vf)
subtract