Contributed by:
Average velocity, Derive equations of motion from the graph, Equations of motion for uniformly accelerated motion, Solving kinematics problems
1.
Equations of Uniform
Accelerated Motion
Mr. Berman
2.
Average Velocity
v = ½ (vf +vi)
3.
•Displacement in terms of Average
Velocity and Time
d= v t
d= ½ (vf + vi) t
4.
How do we derive d= ½ (vf + vi)t from the
vf
vi
o
t Time (s)
•Hint: Area Under the Line=Displacement Δd or simply d
5.
Displacement (d) in terms of vi , a, t
d= vit + ½ at2
6.
How do we derive d= vit + ½ at2 ?
Hint: Start with d= ½ (vf + vi)t and then
substitute for vf that vf = vi+at.
7.
•Final Velocity in terms of vi, a, d
vf2 = vi2 + 2ad
8.
How do we derive vf2 = vi2 + 2ad ?
Hint: Start with d= ½ (vf + vi)t and then
substitute for t = (vf – vi) /a .
9.
vf= vi+ at
vavg = ½ (vf +vi)
of Motion d= ½ (vf + vi)t
for Uniform d= vit + ½ at2
Motion vf2 = vi2 + 2ad
d is the displacement (or
Δd)
Assume that ti=0
10.
Solving Kinematics Problems
Draw a labeled vector diagram showing the
positive and negative direction.
Make a list of the givens (include signs as
needed) and unknown.
Decide what equation(s) you should use.
Write the equation(s) and solve for the
unknown. Always include units in your first
substitution and in your final answer.
11.
Problem 1
A rocket travelling at +95m/s is
accelerated uniformly to +150m/s in 10s.
What is the displacement?
12.
Problem 2
An airplane has a minimum take off
velocity of 80m/s. How long should the
runway be, if the airplane can accelerate
on the ground at 3m/s2 ?
Answer: 1,067m
13.
Problem 3
An airplane landing at +100m/s, comes to
a stop in 30s.
1. What is the acceleration?
2. How far did it travel on the runway before it
stopped?
Answer: -3.3m/s2, 1,515m
+1-315-636-4485
+91 98151-74050 
