Physical Science
Unit 3 Warm-Up
Work, Power and Simple Machines
Wednesday 9/18/13
• Define Work
• Give an example of work
• Turned in on Tuesday
–Unit 2 review, remember you
MUST have shown work for math
problems b/c I gave out answers.
9/19/13
• Label the following as work or not work
1. Sliding a box across the floor
2. Lifting the box
3. Carrying the box to the next room
4. Lowering the box to the floor
5. Holding 200 lbs box over your head
9/20/13
• Use your formula sheet to write the equation
that would go with the following units. HINT:
first look at what each unit measures.
1. Kg, N
2. mL, g
3. s, m
4. W, s
5. m, N
6. m/s2, s
9/23/13
• EOCT review
• How long does it take for a car that traveled 25
m to reach a speed of 15.25m/s?
9/24/13
• Have out “Simple Machine Practice”
• Identify the simple machine that is in the
complex machine below
1. Screw Driver
2. Stage Curtains
3. Flight of stairs
4. Nail
5. Hammer putting in a nail
6. Shovel
9/26/13
• Quiz Friday:
• How much power is used if it take 25 N of
force to move box 13.5 m in 45 seconds?
9/30/13
• Turn in Chapter 14 Vocab Review at the start
of the period.
• Warm-Up
• How much time does it take to use 375 watts
of power if 285 J of work was done?
10/1/13
• What is a compound machine?
• Why is efficiency of a machine always less than
100 %?
10/2/13
A crane lifts a 875 N load a height of 15 m in 95
s. What is the power of the crane?
Warm-Ups Due today. From 9/18/13 to
10/2/13 should have 9 warm-ups. Questions are
on teacher web-page if you’ve lost your answers