What is the equation for density?
- write it in symbol & word
density = mass / volume
p=m/v
What is the equation for speed?
- write in symbol and word
speed = distance / time
v=d/t
What is the equation of gravitational field strength?
- write in word & symbol
gravitational field strength = weight / mass
g = W/m
What are two instruments needed to measure density?
balance (electric balance)
measuring cylinder (filled with water)
What are two instruments needed to calculate speed?
timer (stop watch)
ruler (measuring tape)
What is g on Earth?
g = 9.81 N/Kg
How would you find the volume of an 'irregular' object?
Place the object in a measuring cylinder that is filled with water. Record the difference of water level and that will be its volume.
What are two different common units of speed?
m/s and km/h
If g on Planet A is 12.1 N/Kg and the mass of a watermelon is 981 g, what is it's weight?
g = W/m
W = g x m
12.1 N/Kg x 0.981 Kg = 11.87 N
A metal object is weighed and has a mass of 62 grams. Its volume is 29 cm3. Calculate its density
Would the object float or sink?
p=m/v
p=62g/29cm3
p=2.14 g/cm3
This metal object would sink.
A runner runs a 200m race.
He clocks at 25.12 seconds.
What is his average speed?
v=d/t
v= 200m/25.12s
v=7.96 m/s
A driver pushes the petal and moves ahead. Its forward push is 1,200 N and is pushed back from air resistance of 225 N.
Draw a force diagram and calculate its resultant force
225 N <-- Car --> 1200N
RF = 1200 N - 225 N
RF = 975 N
This object is known to have the density of 0.72 g/cm3. It weighs as 12.6g. Calculate its volume.
p=m/v
v=m/p
v=12.6g/0.72g/cm3
v= 17.5 cm3
Create a speed-time graph of:
0s = 0m/s
30s = 7 m/s
40 s = 7 m/s
50 s = 7 m/s
60s = 0ms
Calculate its total distance travelled.
create an accurate graph
area of triangle + area of rectangle = distance travelled.
Distance travelled = 280m
A ball on Earth has W = 112N. On Planet A, its W = 82N.
Find out what the gravity on Planet A is?
Earth:
W = 112 N; g = 9.81 N/Kg
g = W/m ; m = W/g
m = 112N / 9.81 N/Kg
m =11.4 Kg
Planet A:
W = 82N & m = 11.4 Kg
g = W/M --> 82N/11.4Kg
g = 7.19 N/Kg