Exam 1: (constant acceleration-circular motion)

Question 1

T/F horizontal motion affects vertical motion and vice versa?

Answer 1

False
- aside from effects of air resistance

Question 2

vector

Answer 2

an arrow in space with particular properties

Question 3

vector properties (2)

Answer 3

1. magnitude => length of arrow
2. direction the arrow points

Question 4

how can you break up a vector on a graph?

Answer 4

break up position, velocity, and acceleration to horizontal and vertical parts
- u(arrow) = X î + Y j

Question 5

position vector

Answer 5

is an arrow from the origin to the particle
- components of the vector are the objects coordinates

Question 6

acceleration components (2)

Answer 6

• magnitude is the total acceleration
• direction of acceleration

Question 7

at the highest point only the ______ component of velocity must be zero

Answer 7

vertical
- a vector = o î - (9.8 m/s^2) j^

Question 8

quadratic formula

Answer 8

(-b +- sqrt(b^2 - 4ac))/2a

Question 9

for horizontal acceleration constants, does velocity change in free fall and projectile motion? what happens to a?

Answer 9

velocity never changes in free fall and projectile motion so a = 0 m/s^2

Question 10

what does acceleration tell you about velocity?

Answer 10

how quickly velocity is changing
- with motion along a line it means speeding up or slowing down

Question 11

what happens with constant velocity?

Answer 11

there is 0 acceleration

Question 12

what can 2D motion mean? (2)

Answer 12

• speed changing
• object changing

Question 13

T/F velocity cannot change if speed doesn’t?

Answer 13

False, it can

Question 14

how do you visualize acceleration vector direction? (5)

Answer 14

1. draw objects path
2. draw velocity vector, tangent to path in direction of motion
3. determine if velocity is speeding up or slowing down
4. determine if the object is turning
5. determine total acceleration vector

Question 15

how do you draw a parallel if an object is speeding up?

Answer 15

in the same direction as the velocity vector

Question 16

how do you draw a parallel if the object is slowing down?

Answer 16

in the opposite direction of the velocity vector

Question 17

if an object is turning how do you draw a perpendicular?

Answer 17

in the direction the object is turning at 90 degrees

Question 18

if both a parallel and a perpendicular are non zero, what does that mean for a vector total acceleration?

Answer 18

a total acceleration vector is between the directions of a parallel and a perpendicular

Question 19

if an object is not turning do you need a parallel and a perpendicular?

Answer 19

you need a parallel but a perpendicular is zero
- speed change with no turning

Question 20

if an object has constant speed around a circular path do you need a parallel and a perpendicular?

Answer 20

with a constant speed no a parallel is needed (=0) but a perpendicular is included

Question 21

what is the circular motion equivalent to a parallel?

Answer 21

a tan => tangential acceleration

Question 22

what is the circular motion equivalent to a perpendicular?

Answer 22

a cen => centripetal acceleration

Question 23

what is the equation for a cen calculations?

Answer 23

V^2/R where V is speed of the object and R is the radius of the circular path

Question 24

uniform circular motion

Answer 24

no speed change so a tan is not needed for speed change

Question 25

non uniform circular motion

Answer 25

both a tan and a cen are used because there is turning and speed changes

Question 26

T/F circular motion is constant acceleration?

Answer 26

False, it never is because constant acceleration requires the same direction and magnitude - a vector total acceleration is always changing in circular motion

Question 27

steps for circular motion problems (7)

Answer 27

1. choose where the circle is visible => usually top down view 2. choose point on the path to analyze 3. draw V vector 4. draw a tan vector 5. draw a cen vector 6. calculate a cen with eq 7. find a vector total acceleration

Question 28

what can a centrifuge do? (3)

Answer 28

1. separate red blood cells from blood 2. isolates organelles from cells 3. concentrate DNA in the sample as fractions

Question 29

relative acceleration

Answer 29

multiply by 9.8 m/s^2 to find typical acceleration - otherwise means times g force

Question 30

end card

Answer 30

:)