Transcript V = (Vi + Vf)/2 Vf = Vi + at Vf2 = (Vi2 + 2aΔd) Δd = Vit

AVERAGE VELOCITY:
V = d/t
V = (Vi + Vf)/2
Final Velocity:
Changing A= Δv/t gives you:
Vf = Vi + at
On reference table
FINDING VALUES WITHOUT TIME:
Vf2 = Vi2 + 2ad
Ex: A car traveling at 14m/s brakes until it has a
velocity of 10 m/s. If it traveled 30m, what is
the cars acceleration?
(10m/s)2= (14m/s)2 +2 (A)(30m)
100 = 196+60A
- 96 = 60A
A= -1.6 m/s2
DISPLACEMENT FORMULA:
d = Vit + 1/2at2
Ex: A car traveling with a velocity of 10m/s
accelerates at a rate of 3m/s2 for 5.0 seconds.
How far does it travel ?
d= 10m/s(5sec) + ½ (3m/s2)(5sec)2
d= 50m + ½(75m)
d= 50m + 37.5m
d= 87.5m
SOLVING PROBLEMS
• Carefully read problem
• List and label information
• Determine which formula
to use
• Plug in values
• Calculate
• Write the answer with units
Dimensional Analysis: Showing units on
both sides of a formula are consistent
Vf = Vi + A(t)
m/s = m/s + m/s2(s)
m/s = m/s + m/s
(correct)
d= V/(2A)
m = (m/s)/(m/s2 )
m = (m/s)(s2/m)
m≠s
(bad formula)