Chapter 1
Chapter 2
Chapter 3
Chapter 4
100
What is the equation for density?
- write it in symbol & word
density = mass / volume
p=m/v
100
What is the equation for speed?
- write in symbol and word
speed = distance / time
v=d/t
100
What is the equation of gravitational field strength?
- write in word & symbol
gravitational field strength = weight / mass
g = W/m
100
if m=Fxd
How would you find a distance?
d = m/F
distance is moment divided by force
200
What are two instruments needed to measure density?
balance (electric balance)
measuring cylinder (filled with water)
200
What are two instruments needed to calculate speed?
timer (stop watch)
ruler (measuring tape)
200
What is g on Earth?
a) what the true gravity units are
b) what you will use by Cambridge
a) g = 9.81 N/Kg
b) g = 10 N/Kg
200
What is the centre of gravity and how would you make the center of gravity lower on a bus?
The centre of gravity is an imaginary line where all the mass of an object could be located there.
To make the centre of gravity lower, have more people sit on the lower portion of the bus or make it closer to the ground.
300
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.
300
What are two different common units of speed?
m/s and km/h
300
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
300
The man uses a shadoof to collect water. If the water has a weight of 1200N and the distance of the arm from the pivot is 2.2 m. What is the moment?
m =Fxd
F=1200N ; d = 2.2m
m = 1200N x 2.2m
m=2640Nm
400
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.
400
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
400
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
400
This boy is sitting on a seesaw with his friend, and it is balanced. His weight is 260 N, and he is 1.2 m away from the pivot. His friend is also 1.5 metres away. What is his weight?
m1 = m2 ; m=Fxd
m1=260N x 1.2m
m1= 312 Nm
m2=312Nm so...
312Nm = F x 1.5m ; F = 321Nm/1.5m
F=208N
500
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
500
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
500
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
500
This seesaw is in equalibrium.
An older sister is sitting on the left side, and on the right are her two little brothers.
She is 0.5m away from the pivot and boy1 is 0.5m and boy2 is 1.0m.
Boy1 weighs 20N and Boy2 weighs 15N.
What is the weight of the older sister?
m1 = m2 ; m=Fxd
m2 = (0.5mx20N) + (1.0mx15N)
m2 = 10Nm + 15 Nm ; m2=25 Nm
m1=m2 so m1 =25Nm
25Nm = F x 0.5m
F=25Nm/0.5 ; F=50N