# CH 8 Flashcards Preview

## 2018 PHYSICS 10 CONCEPTUAL > CH 8 > Flashcards

Flashcards in CH 8 Deck (32)
1
Q

What is work?

A

FORCE X DISTANCE (in the direction of the applied force). Measured in JOULES

2
Q

If you drag a block 20m with 5N or force, how much work did you do?

A

100 newton meters, or 100 JOULES

3
Q

IF WORK=FORCExDISTANCE, then DISTANCE=

A

WORK/FORCE

4
Q

IF WORK=FORCExDISTANCE, then FORCE=

A

WORK/DISTANCE

5
Q

If you do 10 joules of work over 5 meters, how much force?

A

WORK/DIST= FORCE so 10 Joules/ 5 meters = 2 NEWTONs

6
Q

If you do 20 joules of work using 5N of force, how far did you go?

A

WORK/FORCE=DISTANCE so 20 joules/ 5 newtons= 4 meters

7
Q

What is POWER? (two ways)

A

WORK/TIME or FORCE*DISTANC/TIME. It measures the rate of work, how fast you can do the work

8
Q

What is ENERGY?

A

Ability to do work. Like stored work.

9
Q

What are the units of ENERGY?

A

JOULES - think of it as “work waiting to be done” or “stored work”

10
Q

How is work different from energy?

A

WORK is being done, Energy is work waiting to be done, like a battery wating to be used.

11
Q

How is work different from power?

A

Work is force*distance, and power is an amount of work per unit of time. It is work/time. Power is a RATE OF DOING WORK, basically, how fast you can do the work.

12
Q

What is the unit of work we use?

A

JOULE (newton*meter)

13
Q

What is the unit of power we use?

A

WATT (joule/sec) or (newton*meter/second)

14
Q

What is the unit of energy we use?

A

JOULE (newton*meter)

15
Q

Explain FORCE units two ways

A

Newton or kg*m/s2

16
Q

Explain POWER units three ways

A

WATT or joule/s or kg*m2/s3

17
Q

Explain WORK units three ways

A

JOULE, or Nm, or kg*m2/ s2

18
Q

What is potential energy?

A

mgh- non-moving stored energy. from HEIGHT.

19
Q

What is kinetic energy?

A

one half mass velocity squared. MOVING energy.

20
Q

You lift 8kg up 5 meters, How many JOULES?

A

400 Joules

21
Q

You lift 8kg up 5 meters in 4 seconds, how many WATTS of power?

A

100 watts

22
Q

You lift 8kg up 5 meters in 20 seconds, how many WATTS of power?

A

20 watts

23
Q

there are ______ of FORCE, ____ of WORK ,______ of POWER and _____ of ENERGY

A

NEWTONS of force, JOULES of work, WATTS of power and JOULES of energy

24
Q

EQN relating change in PE to change in KE

A

mg(delta h)= 1/2 m(delta v)2

25
Q

Conservation equation

A

PEo+KEo = PEf +KEf or mgh+1/2 mv2 = mgh + 1/2 mv2 (notice the mass can cancel if it doesn’t change)

26
Q

How much energy in a 25kg block 4meters high?

A

PE= mgh = 25104 = 1000 J

27
Q

How much energy in a 4kg block traveling 3 m/s

A

KE = mv2/2 = 4*3^2 / 2 = 36/2 = 18 J

28
Q

How much power if you move 50 kg 20 meters in 10 seconds?

A

P = Fd / t = 50*20/10 = 100 WATTS

29
Q

WATTS measure ____

A

Power

30
Q

NEWTONS measure____

A

Force

31
Q

JOULES measure _____

A

Work and Energy

32
Q

What are the two energies we talk about in this unit?

A

Potential (height) and Kinetic (speed)