Chapter 5 & 6 Physics

Question 1

Scalar Quantities

Answer 1

describe only magnitude (speed, distance, and time)

Question 2

Vector Quantities

Answer 2

describe magnitude and direction (velocity, displacement, and position)

Question 3

Distance

Answer 3

Δd (scalar) (how far an object travels along a given path)

Question 4

Displacement

Answer 4

Δd (vector) (how far an object is from the starting point and in what direction)

Question 5

Position

Answer 5

where an object is at a given time in relation to a reference point

Question 6

Calculating Displacement

Answer 6

Δd = d2 (final position) - d1 (starting position)

Question 7

Indicating Direction with Vectors

Answer 7

•Can be indicated by:
-Compass directions (North, East, South, West)
-Up and down
-Left and right
-A positive or negative sign
•North and west often considered positive, south and west often considered negative

Question 8

Drawing Vectors

Answer 8

vectors are drawn to scale and at the correct angle using a protractor and a ruler ((20m {N 20 degrees E})

Question 9

Adding Vectors

Answer 9

•Drawn tip to tail
•Vectors in the same direction can be added to find total displacement
•Vectors going in different directions can be negatively added or subtracted to find total displacement

Question 10

Speed

Answer 10

v = Δd (meters)/Δt (seconds) (the distance travelled by an object divided by the the time it was travelling)

Question 11

Velocity

Answer 11

v = Δdisplacement/Δtime (the displacement of an object divided by the time it was travelling)

Question 12

Graphing Velocity

Answer 12

•Uniform Motion: motion with no change in velocity
•Velocity is the slope of the position vs time graph (slope of position time graph = v)

Question 13

Line of Best Fit

Answer 13

•Do not use actual data points when calculating slope (most don’t lie directly on the line)
•Don’t assume that the points (0,0) is a data point

Question 14

Acceleration

Answer 14

•A change in velocity during s time interval
•Negative = slowing down, positive =speeding up
•Measured in m/s2
•A = Δv/Δt (seconds) or a = v2 - v1/t2-t1
•Graphed in velocity versus time graph
If the velocity time graph is a straight line, acceleration is constant
•Motion with constant acceleration is called uniformly accelerated motion
•Acceleration due to gravity: influence by gravity, an object is uniformly accelerated at a rate of 9.81 m/s2

Question 15

Force

Answer 15

F= m(kg )a(m/s2) (units = newtons (N)) (influenced on an object causing it to move

Question 16

Work

Answer 16

W= Fd or W= mad (force applied over a distance)

Question 17

Kinetic Energy

Answer 17

Ek = mv2/2 (the energy of motion) (J = kg • m2/s2)

Question 18

Potential Energy

Answer 18

•Energy stored in a substance or object due to its position or condition
•Forms of potential energy:
-Elastic potential energy
-Chemical potential energy
-Nuclear potential energy
-Gravitational potential energy
•Gravity is a property of anything that has mass and depends on the height of objects
•Weight = the force of gravity (Fg = mg or W = ΔEg)
•Gravitational Potential Energy:
-Eg = m(kg)g(9.81)Δh
-Weight = FΔd
-Weight = FgΔh
-Weight = mgΔh

Question 19

Pendulums

Answer 19

continuously covert between Eg to Ek

Question 20

Efficiency

Answer 20

Eout/Ein x 100 (ratio of useful output energy to input energy expressed in a percent)

Question 21

Energy Efficiency and the Environment

Answer 21

no process is 100% efficient, some energy will always be converted to thermal energy due to friction