Physics Chapter 1 Test Questions

Questions and Answers

What is the role of equations in this book?

Equations (formulas) show the relationships between concepts in science, for example, a = f/m shows the relationship between acceleration, mass, and force.

Outline some features of the scientific method.

Question 2. Gather data 3. Make hypothesis (educated guess) 4. Test hypothesis with an experiment 5. Adjust hypothesis if needed

Distinguish among a scientific fact, hypothesis, law, and theory: fact is a well established _; hypothesis is an educated _; law is a proven _; theory is a hypothesis that most _ with.

belief, guess, theory, agree

What test can you perform to increase the chance in your own mind that you are right about a particular idea?

Scientific method Signup and view all the answers

Clearly distinguish between science and technology.

Technology is the application of science for practical uses. Signup and view all the answers

Why is physics considered to be the basic science?

Because it studies the most basic things in nature such as energy. Signup and view all the answers

What did Galileo discover in his legendary experiment at the Leaning Tower of Pisa?

He discovered that objects with different weights hit the ground at the same time. Signup and view all the answers

What did Galileo discover about moving bodies and force in his experiments with inclined planes?

Galileo discovered that force on an object changes its velocity. Signup and view all the answers

What does it mean to say that a moving object has inertia? Give an example.

A moving object has inertia because it will keep moving by itself. Example: A bowling ball keeps moving without needing to be pushed along. Signup and view all the answers

Cite Newton's first law of motion.

An object's mass has inertia which results in changes to the object's motion. Signup and view all the answers

What is the net force on a cart pulled to the right with 100 pounds and to the left with 30 pounds?

70 lb to the right. Signup and view all the answers

Why do we say that force is a vector quantity?

Force is a vector because it has a direction. Signup and view all the answers

What is the net force on an object pulled with 80 newtons to the right and 80 newtons to the left?

0 N. Signup and view all the answers

What does it mean to say something is in mechanical equilibrium?

Mechanical equilibrium is when the net force on the object (sum of all forces) equals 0 N. Signup and view all the answers

Consider a book that weighs 15 N at rest on a flat table. How many newtons of support force does the table provide? What is the net force on the book in this case?

Support Force = 15 N, Net Force = 0 N. Signup and view all the answers

A bowling ball at rest is in equilibrium. Is the ball in equilibrium when it moves at constant speed in a straight-line path?

True Signup and view all the answers

If a bird sitting in a tree is traveling at 30 km/s relative to the faraway Sun, when the bird drops to the ground below, does it still go 30 km/s, or does this speed become zero? What is the key word that explains this?

If a bird moving forward at 30 km/s falls, it is still moving forward at 30 km/s while falling because its inertia keeps its forward motion. Signup and view all the answers

What two units of measurement are necessary for describing speed?

Distance and time. Signup and view all the answers

Distinguish between instantaneous speed and average speed.

Average speed is over a period of time, e.g., 200 miles in 4 hours, average speed is 50 mi/hr; instantaneous speed is what the speedometer shows at a certain moment. Signup and view all the answers

What is the average speed in kilometers per hour for a horse that gallops a distance of 15 km in a time of 30 minutes?

30 km/hr. Signup and view all the answers

How far does a horse travel if it gallops at an average speed of 25 km/hr for 30 minutes?

12.5 km. Signup and view all the answers

Distinguish between speed and velocity.

Velocity = speed + direction. Signup and view all the answers

If a car moves with a constant velocity, does it also move with a constant speed?

False Signup and view all the answers

What is the acceleration of a car that increases its velocity from 0 to 100 km/hr in 10 seconds?

10 km/hr². Signup and view all the answers

Study Notes

Equations and Science

Equations illustrate relationships between scientific concepts; for example, ( a = \frac{f}{m} ) relates acceleration, force, and mass.

Scientific Method Features

Steps include:
- Formulating a question
- Gathering data
- Making a hypothesis (educated guess)
- Testing the hypothesis through experimentation
- Adjusting the hypothesis as necessary.

Distinctions in Science

Scientific fact: a well-established truth.
Hypothesis: a testable educated guess.
Law: a hypothesis that has been consistently proven true.
Theory: a widely accepted hypothesis supported by substantial evidence.

Testing Ideas

Utilizing the scientific method enhances confidence in specific ideas or concepts.

Science vs. Technology

Technology is defined as the practical application of science to fulfill human needs.

Role of Physics

Physics is termed the basic science because it explores fundamental elements of nature, particularly energy.

Galileo's Discoveries

During the Leaning Tower of Pisa experiment, Galileo found that objects of differing weights fall simultaneously.
His inclined plane experiments revealed that force affects an object's velocity.

Inertia Explained

Inertia in motion means an object continues moving without external force; for example, a bowling ball keeps rolling after being pushed.

Newton's First Law

Newton's first law indicates that an object's mass confers inertia, which influences its motion.

Net Force Calculations

When a cart is pulled with 100 pounds to the right and 30 pounds to the left, the net force is 70 pounds to the right.
If an object is pulled with equal forces (80 newtons) in opposite directions, the net force is 0 newtons.

Mechanical Equilibrium

Mechanical equilibrium occurs when the net force acting on an object equals 0 newtons, indicating no acceleration.

Support Force and Net Force

A 15 N book at rest on a flat table experiences a support force of 15 N. The net force acting on the book is also 0 N.

Equilibrium in Motion

A bowling ball maintains equilibrium both at rest and when moving in a straight line at constant velocity since net force remains 0 N.

Inertia and Motion

As a bird falls, it retains its forward motion of 30 km/s due to inertia, despite its vertical descent.

Measuring Speed

Speed is defined by the formula ( S = \frac{d}{t} ), requiring distance and time measurements.

Speed Types

Average speed is calculated over a time interval; for instance, traveling 200 miles in 4 hours results in an average speed of 50 miles per hour.
Instantaneous speed refers to what is displayed on a speedometer at any given moment.

Example Calculations

The average speed of a horse covering 15 km in 30 minutes (0.5 hours) is 30 km/h.
A horse galloping at 25 km/h for 30 minutes travels 12.5 km.

Speed vs. Velocity

Velocity includes both speed and direction, differentiating it from speed alone.

Constant Velocity Consideration

A car can have constant speed while changing direction, leading to variable velocity.

Acceleration Calculation

Acceleration of a car increasing velocity from 0 to 100 km/h in 10 seconds is calculated as:
- ( a = \frac{V_f - V_i}{t} = \frac{100 \text{ km/h} - 0}{10 \text{ s}} = 10 \text{ km/h/s} ).

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Description

This quiz focuses on key concepts from Chapter 1 of a physics textbook, including the role of equations in science and the features of the scientific method. Prepare to test your understanding and retention of foundational physics principles. Ideal for students seeking to reinforce their learning.