What is a force in physics?
A force is a push or pull on an object.
What causes a force on an object?
Interaction with another object causes a force.
What effects can a force have on an object?
It can make the object move, change speed, direction, shape, or several effects.
What effect does hitting a moving ball with a bat have?
It changes the ball's direction.
What effect does pressing an inflated balloon have?
It changes the balloon's shape.
What is required for a force to come into play?
At least two objects must interact.
What is the SI unit of force?
The newton.
What is the symbol for the newton?
N.
What happens to forces when two objects interact?
Each object experiences a force from the other.
When do forces between two interacting objects disappear?
When the interaction ceases.
When does a contact force act between objects?
Only when there is physical contact between the objects.
What causes muscular force in the body?
The action of muscles contracting and elongating.
When does friction act on an object?
When an object moves or tries to move over another surface.
What direction does friction oppose?
The direction of motion or attempted motion.
What causes friction between surfaces?
Irregularities in contacting surfaces that lock into one another.
On which surfaces is friction greater?
On rough surfaces rather than smooth surfaces.
What is a non-contact force?
A force affecting objects without physical contact.
What does magnetic force act on without physical contact?
Another magnet or magnetic material.
What bodies does electrostatic force act upon?
Charged or uncharged bodies.
What happens when two objects are rubbed together?
They become oppositely charged with static electricity.
What are the two kinds of static charge produced by rubbing?
Positive and negative charges.
What is gravitational force?
The Earth's attractive force pulling objects toward itself.
What happens to an object moving upward under gravity?
It slows down until it stops momentarily at the top.
What happens after an object stops at the top during vertical motion under gravity?
It moves downward with increasing speed.
What is weight?
The force with which the Earth pulls an object toward itself.
What is the SI unit of weight?
The newton, symbolized as N.
Why does a spring balance measure weight?
Because hanging an object stretches its spring.
How is the weight read on a spring balance?
By reading the amount of spring stretching on a scale marked in newtons.
What is the range of the illustrated spring balance?
0 to 10 newtons.
What is the smallest measurable division on the illustrated spring balance?
0.2 newtons.
What happens if an object is heavier than a spring balance's maximum value?
The instrument may be damaged.
What does mass measure in an object?
The amount of matter in the object.
How does weight differ from mass across locations?
Weight varies due to gravitational force differences.
What is the weight of a 1 kg mass on Earth?
10 newtons.
What is the weight of a 1 kg mass on the Moon?
1.6 newtons.
What is the weight of a 1 kg mass on Mars?
3.8 newtons.
What is the weight of a 1 kg mass on Jupiter?
25.4 newtons.
Is it scientifically correct to use kilograms for mass?
Yes, kilograms correctly describe mass scientifically.
How is mass often referred to in everyday speech?
Mass is often called weight in everyday speech.
What is buoyant force in a liquid?
It is the upward force applied by a liquid on an object.
When does an object sink in a liquid?
When its gravitational force is greater than the buoyant force.
When does an object float in a liquid?
When its gravitational force equals the buoyant force.
What does Archimedes’ Principle state about immersed objects?
They experience an upward force equal to the weight of displaced liquid.
Which author formulated the principle about upward force on immersed objects?
Archimedes.
Why can pumice float on water?
Because it is less dense than water due to air pockets.
Test your knowledge with 22 questions on Exploring Forces.
1. What is a force in physical science?
2. Which situation best represents a force acting as a pull?
Review the complete course in the study sheet for Exploring Forces.
See study sheet →Import your course and AI generates flashcards in 30 seconds.
Flashcard generator