Gravity, Force
and Levers
Student Name:
Class:
Teacher Name:
School:
www.discoversensors.ie
Discover Sensors Formative Assessment Question
Question 1
a) Isaac Newton observed an apple fall from the tree to the ground.
What did Newton call the force that pulls the apple towards the ground?
Name one other discovery made by Newton.
b) The picture shows the planet Earth.
The man standing on the Earth is experiencing the force of gravity. Using an arrow
on the diagram, show the direction of that force.
What would happen to the man if there was no gravity?
www.discoversensors.ie
© Discover Science & Engineering
Discover Sensors Formative Assessment Question
c) The value for acceleration due to
gravity (g) is 10 m/s2 on Earth
and 1.6 m/s2 on the Moon
(approx.values).
The mass of the astronaut is 80 kgs on Earth.
What would the mass of this astronaut be
on the Moon?
The kilogram is the unit of mass.
What is the unit of weight?
The weight of an object is equal to the mass x acceleration due to gravity: W= m x g.
Calculate the weight of this astronaut on the Earth.
Calculate the weight of this astronaut on the Moon.
C
© Discover Science & Engineering
www.discoversensors.ie
Discover Sensors Formative Assessment Question
d)In 1589, the Italian scientist Galileo
dropped two balls of different masses
from the Leaning Tower of Pisa.
Which one reached the ground first?
Explain your answer:
If he dropped a sheet of paper and a steel ball, which would reach the ground first?
Explain your answer:
If the experiment with a sheet of paper and a steel ball was repeated in a vacuum,
would Gallileo have obtained the same result? Explain your answer.
What difference do you think, if any, rolling the paper into a ball before dropping it
would make?
How do builders use a plumb line to check if a wall
or a joint is vertical?
What could you use to make a plumb line?
www.discoversensors.ie
© Discover Science & Engineering
Discover Sensors Formative Assessment Question
Question 2
a) A weightlifter lifts two 70 kg masses from
the floor to a height of 2 m above the
floor in 3 s .
Calculate the total weight the man is lifting. (The value for acceleration due to
gravity (g) is 10 m/s2 on Earth).
Calculate the work done by the weightlifter in lifting the weights.
Calculate the average power generated by the weightlifter.
N.B. Make sure you have units for all your answers.
© Discover Science & Engineering
www.discoversensors.ie
Discover Sensors Formative Assessment Question
b) There are three states of equilibrium – stable, neutral and unstable.
What is the state of equilibrium shown in each of the following diagrams?
Fig. 1
Fig. 2
State of equilibrium of the ball (Fig. 1):
Explain your answer:
State of equilibrium of the cone (Fig. 2):
Explain your answer:
A student needs to find the centre of gravity of an irregular shaped piece of
cardboard. Using the following headings describe how the student found the centre
of gravity of the cardboard piece.
Apparatus.
www.discoversensors.ie
© Discover Science & Engineering
Discover Sensors Formative Assessment Question
Method.
Result.
© Discover Science & Engineering
www.discoversensors.ie
Discover Sensors Formative Assessment Question
Question 3
a) Levers are used in many places in our everyday lives.
Use an arrow in both of the pictures above to indicate the fulcrum of the lever.
Explain why or how the nail puller is a lever.
The diagram below shows two persons on a seesaw.
www.discoversensors.ie
© Discover Science & Engineering
Discover Sensors Formative Assessment Question
Calculate the clockwise moment of force – Person A side.
Calculate the anticlockwise moment of force – Person B side.
Explain why this see saw is horizontal.
b) A student is used a meter stick suspended from a retort stand and 300 g mass to
tfind the mass of a small stone.
Draw a diagram showing how the experiment was set up.
© Discover Science & Engineering
www.discoversensors.ie
Discover Sensors Formative Assessment Question
What readings did the student need to take?
Write the formula/calculation the student used to find the mass of the stone.
c) This is a drawing of a steel balance used in ancient times to find the mass of a bucket
of potatoes.
Calibrated Scale
Sliding Known Mass
Container To Hold Potatoes
Show, using an arrow, where is the fulcrum in this balance.
www.discoversensors.ie
© Discover Science & Engineering
Discover Sensors Formative Assessment Question
How do you think the shopkeeper used this balance to find the mass of the potatoes?
d) Why is it easier to turn a nut by using a spanner than just by using your fingers?
Why is a door handle on the opposite side of a door to the hinges?
Why is it usually easier to open the car door when you are outside the car than when
you are seated inside the car?
e) You are able to exert a force of 300 N. Use a diagram to show how you would set up a
crowbar to lift a rock which has a weight of 3000 N?
© Discover Science & Engineering
www.discoversensors.ie
Discover Sensors Formative Assessment Question
For teacher use only.
Comment:
How to improve:
www.discoversensors.ie
© Discover Science & Engineering