Simple Machines + formula
Name three simple machines
What are the reactants and products in a chemical reaction?
Reactants are the starting substances; products are the new substances formed.
What are the main sections of a lab report crit B?
Background info, research question, hypothesis, variables, materials, method, data.
Calculate pressure if a 100 N force acts on an area of 2 m². WITH UNIT
P = 100 / 2 = 50 Pa.
What is matter made of?
Atoms and molecules.
Power is calculated how?
Joules/time
Balance this equation: H₂ + O₂ → H₂O
2H₂ + O₂ → 2H₂O.
Explain the difference between independent, dependent, and controlled variables.
Independent: what you change; Dependent: what you measure; Controlled: what you keep the same.
A small motor does 600 joules of work in 12 seconds.
Calculate the power output of the motor.
600/12 = 50W
Name the four states of matter and give one example of each.
Solid (ice), liquid (water), gas (air), plasma (lightning)
"An inclined plane wrapped around a central cylinder" is a description of which simple machine?
What is the word equation for photosynthesis.
Carbon dioxide + water → glucose + oxygen.
Identify one way to make your data collection more reliable.
Repeat measurements and calculate an average.
Convert 500 cm² into km².
0.05m2
0.000005km2
Why does ice float on water?
It’s less dense than liquid water because its molecules spread out when frozen.
A machine has a Power output of 300 W. How many Joules does this machine use in 6 seconds?
300 * 6 = 1800J
Explain why chemical reactions either absorb or release energy.
Energy is absorbed when bonds are broken (endothermic) and released when bonds form (exothermic).
A student finds their data does not match their hypothesis. What should they do in their conclusion?
Explain the results honestly, discuss possible errors, and suggest improvements—don’t change the data.
A ball with a mass of 16 kg is moving at a speed of 3 m/s.
0.5*16*32 = 72J
Describe how the particle model of matter explains temperature.
More movement of atoms --> higher temp.
Explain how Eg and Ek function in a pulley system.
mgh = 0.5m*v2
Balance this equation: C4H10+O2→CO2+H2O
2C4H10+13O2→8CO2+10H2O
Spot the two possible improvements for this table:
time (s) + title
A box of 10 kg is lifted 2 m high in 4 seconds. Calculate the power used.
Work = m × g × h = 10 × 9.8 × 2 = 196 J → Power = 196 / 4 = 49 W.
What is incorrect about the following statement: Evolution is the process in which species adapt to better suit their environment and increase their chances for survival and creating offspring.
Evolution is the process by which populations change over time due to genetic variation and natural selection. Traits that are more favorable for survival and creating offspring lead to adaptation of species over time.