Mechanics Unit 1 Quiz

Questions and Answers

Define velocity.

Velocity is the rate of change of an object's position with respect to time, including direction.

Define acceleration.

Acceleration is the rate of change of velocity with respect to time.

Give an example of velocity.

30 m/s to the east.

Give an example of acceleration.

5 m/s². Signup and view all the answers

What are kinematic equations?

Kinematic equations describe the motion of objects under constant acceleration. Signup and view all the answers

What is the SI unit for force?

Newton Signup and view all the answers

What is the SI unit for energy?

Joule Signup and view all the answers

What is the SI unit for pressure?

Pascal Signup and view all the answers

What is the SI unit for power?

Watt Signup and view all the answers

What is the SI unit for electric charge?

Coulomb Signup and view all the answers

List three things you know about physical quantities.

<ol> <li>They can be classified as base quantities or derived quantities. 2. Examples include length, mass, and time. 3. They can be measured in specific units.</li> </ol> Signup and view all the answers

What is the formula for speed?

Speed = Distance / Time. Signup and view all the answers

Calculate the speed if the distance is 7m and the time is 10s.

0.7 m/s. Signup and view all the answers

Calculate the velocity if the displacement is 5m and the time is 10s.

0.5 m/s. Signup and view all the answers

Study Notes

Definitions of Key Terms

Velocity: The rate of change of displacement, indicating both speed and direction.
Acceleration: The rate of change of velocity over time; can be positive (speeding up) or negative (slowing down).

Physical Quantities

Physical quantities are classified into base quantities (fundamental, e.g., mass, length, time) and derived quantities (obtained from base quantities, e.g., speed, force).
Examples include:
- Base Quantity: Mass (kilogram)
- Derived Quantity: Speed (meters per second)

Kinematic Equations

Kinematic equations relate displacement, initial velocity, final velocity, acceleration, and time for uniformly accelerated motion.

International System of Units (SI)

Base Units: Fundamental units like meter (m), kilogram (kg), second (s).
Derived Units: Combinations of base units. Examples include:
- Newton (N): kg·m/s²
- Joule (J): kg·m²/s²
- Pascal (Pa): kg/(m·s²)
- Watt (W): kg·m²/s³
- Coulomb (C): A·s

Motion and Graphs

Understand the distinction between distance (total path length) and displacement (change in position).
Speed is a scalar quantity (magnitude only), while velocity is a vector quantity (magnitude and direction).

Calculating Speed and Velocity

Speed Calculation: Speed = Distance / Time
- Example: Distance = 7m, Time = 10s → Speed = 7/10 = 0.7 m/s
Velocity Calculation: Velocity = Displacement / Time
- Example: Displacement = 5m, Time = 10s → Velocity = 5/10 = 0.5 m/s

Equations of Motion

The four main equations for uniformly accelerated motion involve solving for final velocity, initial velocity, acceleration, time, and displacement.
Example Problem:
- A car accelerates from rest at 4.2 m/s² for 6.5 seconds:
  - Final Speed Calculation: Use final velocity formula
  - Distance Calculation: Use displacement formula

Learning Objectives and Success Criteria

Distinguish between base and derived quantities.
Draw and interpret displacement-time, velocity-time, and acceleration-time graphs.
Apply equations of motion to solve problems for uniformly accelerated motion in one dimension.

Description

This quiz focuses on the fundamental concepts of mechanics, including definitions of velocity and acceleration. You will also reflect on your knowledge of physical quantities and differentiate between base and derived quantities. Test your understanding and reinforce your learning of these key physics concepts.