Don't guess... GUESS!
What do the G and U in GUESS stand for?
Givens and Unknowns (your first step in tackling problems!)
A car moves 158m forwards before reversing and traveling for 682m backwards. What is the car's displacement?
Displacement is a vector! Cares about direction.
Forwards positive, backwards negative
Δx = 158m - 682m
Δx = -524m
A car with a velocity of 8.4 m/s travels for 505 seconds. How far does it travel?
v = Δx / Δt
v * Δt = Δx
8.4m/s * 505s = Δx
4242m = Δx
If an object is at rest, what is its velocity?
0m/s
What do you Solve your equation for? (remember: this is the first S!)
The unknown! (get the Unknown alone!)
Over 11 seconds, an apple rolls 22m. What is its average velocity?
v = Δx / Δt
v = 22m / 11s
v = 2 m/s
A race car starts at rest and ends up moving -75.8 m/s. If the acceleration of the race car was -6.064 m/s2, how long was it in motion?
a = Δv / Δt
a * Δt = Δv
Δt = Δv / a
Δt = (-75.8m/s - 0m/s) / -6.064m/s2
Δt = 12.5 s
If an object is decelerating, what does this mean acceleration will be?
Negative
Anytime you Solve to get a variable alone, what order do you follow?
SADMEP (reverse PEMDAS)
A car starts at rest, and accelerates until it reaches a velocity of 18.6 m/s. If this takes 8 seconds, what was the acceleration of the car?
a = Δv / Δt
a = (v - vi) / Δt
a = (18.6m/s - 0m/s) / 8s
a = 2.325 m/s2
An astronaut blasting off into space experiences 8.2m/s2 of acceleration over 81.2s. What is the change in velocity they experience?
a = Δv / Δt
a * Δt = Δv
8.2m/s2 * 81.2s = Δv
665.84 m/s = Δv
What can you find by looking at the slope of a velocity vs time graph?
v = vi + at
Solve this equation for vi.
vi = v - at
A fish starts swimming at 8.4m/s and after 62.5 seconds, ends up at rest.
What is the acceleration of the fish?
a = Δv / Δt
Δv = (v - vi)
a = (0m/s - 8.4m/s) / (62.5s)
a = -0.1344 m/s2
If you didn't say negative, it's wrong!!!
An object is traveling along with a velocity of 5.16 m/s when it accelerates at -1.51 m/s2 for a time period of 6.63 s. What is the final velocity of this object?
v = vi + at
v = 5.16m/s + (-1.51m/s2 * 6.63s)
v = -4.85 m/s
If a car starts at rest and ends at rest, no matter how long it drives, what will be its average acceleration?
0 m/s2
v = vi + at
Solve this equation for time.
v - vi
---------- = t
a
An object is moving along with a velocity of 3.66 m/s. It accelerates at 0.8 m/s2 until it reaches a velocity of 10.12 m/s. How long did this take?
a = Δv / Δt
Δt * a = Δv
Δt = Δv / a
Δt = (10.12m/s - 3.66m/s) / 0.8m/s2
Δt = 8.075s
A dog accelerates at a rate of 4m/s2 over 14s. If he started running at 8m/s, how far did he run?
Δx = vit + 1/2at2
Δx = (8m/s * 14s) + (0.5 * 4m/s2 * 142s)
Δx = 504m
What does the term "kinematics" mean?
(must get BOTH roots)
Kine = movement
Matics = math/study of something