Quick Review Flashcards - Click to flip and test your knowledge!
Question
In science, what is the general term used to describe a push or pull applied to an object?
Answer
Force
Question
What is the standard SI unit of force?
Answer
Newton ($N$)
Question
What is the minimum number of objects that must interact for a force to come into play?
Answer
Two
Question
Which type of force acts only when there is physical contact between the interacting objects?
Answer
Contact force
Question
What specific type of contact force is used when a person lifts a school bag or walks?
Answer
Muscular force
Question
Which bodily process uses muscular force to move food through the alimentary canal?
Answer
Digestion
Question
What is the function of muscular force within the human heart?
Answer
It allows blood to circulate by expanding and contracting heart muscles.
Question
Which force always opposes the motion or attempted motion of an object over a surface?
Answer
Friction (or frictional force)
Question
In which direction does the force of friction always act relative to the direction of motion?
Answer
In the opposite direction
Question
What physical feature of surfaces causes friction when they are in contact?
Answer
Irregularities (or minute irregularities)
Question
How does the nature of a surface affect the magnitude of friction?
Answer
Rough surfaces exert a greater force of friction than smooth surfaces.
Question
Why are aeroplanes and high-speed trains designed with specific streamlined shapes?
Answer
To reduce the force of friction exerted by air or water.
Question
What term describes forces that can be experienced even when objects are not touching?
Answer
Non-contact forces
Question
What happens to the speed of a ball rolling on flat ground due to friction?
Answer
The speed gradually decreases until the ball stops.
Question
What type of force is exerted by a magnet on another magnet or a magnetic material from a distance?
Answer
Magnetic force
Question
How do the 'like' poles (e.g. North-North) of two magnets interact?
Answer
They repel each other.
Question
How do the 'unlike' poles (e.g. North-South) of two magnets interact?
Answer
They attract each other.
Question
What is the name of the force exerted by a charged body on another charged or uncharged body?
Answer
Electrostatic force
Question
How are static charges typically built up on the surface of objects like plastic scales or balloons?
Answer
By rubbing the objects together.
Question
What is the interaction between two objects that have acquired similar (like) electrical charges?
Answer
They repel each other.
Question
What is the interaction between two objects that have acquired opposite (unlike) electrical charges?
Answer
They attract each other.
Question
What is the name of the force with which the Earth attracts all objects towards itself?
Answer
Gravitational force (or gravity)
Question
Unlike magnetic or electrostatic forces, what is the constant nature of gravitational force?
Answer
It is always an attractive force.
Question
Why is gravitational force classified as a non-contact force?
Answer
It acts on objects without requiring physical contact.
Question
What happens to the speed of an object thrown vertically upwards as it rises?
Answer
The speed decreases until the object momentarily stops at the top.
Question
What happens to the speed of an object as it falls vertically downwards under the influence of gravity?
Answer
The speed increases.
Question
What is the scientific definition of 'weight'?
Answer
The force with which the Earth pulls an object towards itself.
Question
What is the SI unit of weight?
Answer
Newton ($N$)
Question
Which instrument is commonly used to measure the weight of an object in a laboratory?
Answer
Spring balance
Question
On what physical principle does a spring balance operate to measure weight?
Answer
The stretching of a spring due to the Earth's gravitational pull on an attached object.
Question
What is the definition of the 'mass' of an object?
Answer
The amount of matter contained within the object.
Question
How does mass differ from weight in terms of location?
Answer
Mass remains constant everywhere, while weight varies based on gravitational force.
Question
What are the standard units used to measure mass?
Answer
Grams ($g$) or kilograms ($kg$)
Question
Why is the weight of an object on the Moon much less than its weight on Earth?
Answer
The Moon's gravitational force is weaker than the Earth's.
Question
Approximately what fraction of its Earth weight would an object weigh on the Moon?
Answer
One-sixth ($\frac{1}{6}$)
Question
What is the name of the upward force applied by a liquid on an object placed in it?
Answer
Upthrust (or buoyant force)
Question
Under what condition regarding forces will an object sink in a liquid?
Answer
When the gravitational force (weight) is greater than the buoyant force (upthrust).
Question
Under what condition regarding forces will an object float in a liquid?
Answer
When the gravitational force is equal to the buoyant force.
Question
According to Archimedes' Principle, the upward force on an immersed object is equal to what?
Answer
The weight of the liquid displaced by the object.
Question
Why does a mug feel lighter when it is submerged inside a bucket of water?
Answer
The water exerts an upward buoyant force on the mug.
Question
Which specific rock is known for its ability to float on water due to trapped air bubbles?
Answer
Pumice
Question
If an object is at rest, what does this imply about the forces acting upon it?
Answer
The forces acting on the object are balanced.
Question
What is the purpose of an electroscope?
Answer
To determine whether an object is electrically charged.
Question
When a force is applied to a stationary object, what can it cause the object to do?
Answer
Move from its position of rest.
Question
Beyond changing speed or direction, what physical change can a force cause in an object like a balloon?
Answer
A change in shape.
Question
What are the two types of static electrical charges?
Answer
Positive and negative
Question
How does the density of a liquid relate to the buoyant force it exerts?
Answer
The buoyant force depends upon the density of the liquid.
Question
If a spring balance has a range of $0$ to $10\ N$ and has $5$ divisions between each $1\ N$ mark, what is the value of one small division?
Answer
$0.2\ N$
Question
What happens to the interaction between two objects once they stop interacting?
Answer
They no longer experience the force from each other.
Question
When a ball is thrown upwards, which force causes it to slow down?
Answer
Gravitational force (acting downwards).
Question
What happens to the direction of motion of a ball when it reaches its topmost position after being thrown up?
Answer
The direction of motion changes (from upwards to downwards).
Question
Why is the term 'weight' often used incorrectly in everyday language to describe $10\ kg$ of wheat?
Answer
Because $10\ kg$ is a measure of mass, whereas weight should be measured in Newtons.
Question
What does an electric current consist of in an electrical circuit?
Answer
Moving electrical charges.
Question
How is weight related to the pull of a planet?
Answer
Weight measures how strongly an object is pulled by the planet's gravity.
Question
Which force is involved when a fielder stops a fast-moving cricket ball?
Answer
Muscular force (applied as a push/pull interaction).
Question
Why is it easier to slip on a wet or smooth surface compared to a dry, rough one?
Answer
The force of friction is much lower on smooth or wet surfaces.
Question
In the context of forces, what does 'interaction' refer to?
Answer
The process where two objects act upon each other, resulting in a force.
Question
What effect does pressing an inflated balloon have on its properties?
Answer
It changes the shape of the balloon.
Question
Identify the non-contact force that causes a fruit to fall from a tree to the ground.
Answer
Gravitational force
Question
What type of force is responsible for a compass needle pointing North?
Answer
Magnetic force