Gravity is the non-contact force on this sheet while friction always needs contact, and force itself is measured in newtons, so Year 7 opens by sorting forces by contact. A spring balance is the key's measuring instrument and friction opposes motion.
Key Takeaways
The SI unit of force is the newton (Q1).
Gravity is a non-contact force (Q2).
Q3 records a spring balance as a force measurer.
Section A: Multiple Choice Questions (1 Mark Each)
Choose the correct option for each question.
1.What is the SI unit of force?
(a) joule(b) newton(c) pascal(d) watt
2.Which of these is a non-contact force?
(a) friction(b) gravity(c) tension(d) air resistance
3.Which instrument is used to measure force?
(a) ruler(b) thermometer(c) spring balance(d) ammeter
4.Friction always acts in a direction...
(a) the same as motion(b) opposite to motion(c) perpendicular to motion(d) completely random
5.The force that pulls all objects towards the centre of the Earth is called...
(a) magnetic force(b) electric force(c) gravity(d) elastic force
6.When the forces acting on an object are balanced, the object...
(a) accelerates quickly(b) does not change its motion(c) always stops moving(d) changes direction
Section B: Short Answer Type Questions (2 Marks Each)
Show all steps clearly.
7.What is a force?
8.State two effects that a force can have on an object.
9.Define friction and state whether it is a contact or a non-contact force.
10.Why do astronauts float inside a space station even though gravity is still acting on them?
11.Name two contact forces and two non-contact forces.
12.What is the difference between mass and weight?
13.Why does a ball rolling on grass slow down and eventually stop?
14.A spring balance reads 20 N. What does this reading tell you about the object hanging from it?
Section C: Numericals & Word Problems (3 Marks Each)
Apply the concepts to solve the problems. Show all working.
15.A box has a mass of 3 kg. Use the equation weight = mass × g with g = 10 N/kg to calculate the weight of the box in newtons.
16.An object has a weight of 50 N. Using g = 10 N/kg and the equation mass = weight ÷ g, calculate its mass in kilograms.
17.A resultant force of 20 N acts on a trolley and gives it an acceleration of 4 m/s². Using force = mass × acceleration, calculate the mass of the trolley.
18.A spring extends 2 cm for every 1 N of force applied. How much force is needed to stretch the spring by 10 cm?
19.Two forces of 8 N and 6 N act on an object in the same direction. Calculate the resultant force.
20.Two forces of 12 N and 7 N act on an object in opposite directions. Calculate the resultant force and state its direction.
Answer Key
1. b) newton
2. b) gravity
3. c) spring balance
4. b) opposite to motion
5. c) gravity
6. b) does not change its motion
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End of Worksheet
People Also Ask
What is the SI unit of force?
The newton, option (b) in this worksheet (Q1).
Which of these is a non-contact force?
Gravity, option (b) in this worksheet (Q2).
What measures force?
A spring balance, option (c) in this worksheet (Q3).
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