Vectors and Scalars
Displacement
Speed and Velocity
Acceleration
Word Problems
100
A vector has both magnitude and __________.
direction
100
Generally, is displacement to the left represented by a positive or a negative number?
Generally, displacement to the left is represented by a negative number.
100
If Delta D = 10 m and Delta T = 5 s, what is the speed?
The speed is 10/5 = 2 m/s.
100
If the velocity starts a 0 m/s and ends at 30 m/s after 15 seconds, what is the acceleration?
a = (30 - 0)/15 = 2 m/s/s
100
A train covers 60 m between 2 seconds and 4 seconds. What was the train's average speed?
S = 60/(4 - 2) = 60/2 = 30 m/s
200
Is mass a vector or a scalar?
Mass is a scalar.
200
If you start with a displacement of zero and end with a displacement of 10 m. What is Delta D?
Delta D is 10 - 0 = 10 m
200
If the displacement starts at 5 m and it ends at 20 m after 10 seconds, what is the speed?
The speed is (20-5)/10 = 15/10 = 1.5 m/s.
200
If the velocity starts at 8 m/s and ends at 20 m/s after 4 seconds, what is the acceleration?
a = (20 - 8)/4 = 3 m/s/s
200
It took 350 seconds for a train to travel the distance between the two ends of a city at a velocity 100 m/s. How many meters lie between the two ends of the city?
120 = D/350 D = (100)(350) = 35,000 meters
300
Is velocity a vector or a scalar?
Velocity is a vector.
300
If you start with a displacement of 8 m and end with a displacement of 5 m, what is Delta D?
Delta D equals -3 m.
300
If the velocity starts at 20 m/s and ends at 0 m/s after 4 seconds, what is the acceleration?
a = (0 - 20)/4 = -5 m/s/s
300
A car is moving from rest and attained a velocity of 80 m/s after 5 seconds. What is the acceleration of the car?
a = (80 - 0)/5 = 16 m/s/s
400
If north is up and east is to the right, describe "due southwest."
Due southwest would be down and to the left.
400
If you start with a displacement of -4 m and you end with a displacement of -14 m, what is Delta D?
Delta D is equal to -10 m.
400
If the displacement starts at 25 m and ends at 22 m after 12 seconds, what is the velocity?
The velocity is (22-25)/12 = (-3)/12 = -0.25 m/s.
400
If the velocity starts at -14 m/s and ends at -18 m/s after 8 seconds, what is the acceleration?
a = [(-18) - (-14)]/8 = (-4)/8 = -0.5 m/s/s
400
Over the course of 2 seconds, a roller coaster accelerates from a velocity of 10 m/s to a velocity of 26 m/s. What is the roller coaster's acceleration?
a = (26 - 10)/2 = 16/2 = 8 m/s/s
500
If a vector is represented by an arrow, what does the length of the arrow tell you about the vector?
The length of the arrow tells you the magnitude of the vector.
500
If you start with a displacement of -15 m and you end with a displacement of 5m, what is Delta D?
Delta D is equal to 20 m.
500
If the displacement starts at 10 m, what does the displacement end at after 5 seconds at a velocity of -4 m/s?
(D - 10)/5 = -4 D - 10 = -20 D = -10 m
500
If the velocity starts at -20 m/s, what is the velocity after accelerating at 10 m/s/s for 5 seconds?
[V - (-20)]/5 = 10 (V + 20)/5 = 10 V + 20 = 50 V = 30 m/s
500
A baseball is pitched at 40 m/s in a Major League game. The batter hits the ball on a line drive straight toward the pitcher at 50 m/s. If the bat accelerates the ball at -1,800 m/s/s, for how much time is the bat in contact with the ball?
-1800 = [(-50) - 40]/T -1800T = -90 T = (-90)/(-1800) = 0.05 s
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