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