## 37 Questions

Force is a scalar quantity.

False

The S.I. unit of velocity is meter per second squared.

False

Friction is a type of contact force.

True

Gravity is an example of a contact force.

False

Lift is a type of air resistance.

True

The slope of a distance-time graph represents velocity.

True

Newton's second law of motion relates force, mass, and velocity.

False

The work input is always equal to the work output in a machine.

False

A girl walks 200m N, then 300m W then 150m N, then 200m E, then 100m N, then 100m E. The displacement of the girl is zero.

True

A car passes a cyclist traveling at 15m/s, from the frame of reference of the cyclist, the car appears to be traveling at 7m/s.

False

A naughty boy running west at 4m/s on a people mover moving east at 1.5m/s has a velocity relative to a person standing on the carpeted floor of 2.5m/s west.

True

346cm is equal to 3.46m.

True

A car accelerating from 0 to 15m/s in 30 seconds has an acceleration of 0.5m/s^2.

True

If acceleration is zero, velocity must also be zero.

False

A runner completing an 800 meter race in 90 seconds has an average speed of 8.89m/s.

True

Gravity is not a type of friction.

True

Momentum is a product of an object's mass and velocity. Since the velocity is zero, the momentum is also zero.

True

A velocity vs. time graph of a car traveling down the street appearing as a straight line sloping upwards indicates that the car's acceleration is constant.

True

A jaguar accelerating from 0 to 10.3m/s in 3.0 seconds has an acceleration of 3.43m/s^2.

True

The force that opposes your push when you're unable to move an object is gravity.

False

Air resistance is the force that acts on a projectile besides gravity.

True

Mass and weight are exactly the same thing.

False

Rolling friction is always greater than static friction.

False

Objects in free fall eventually reach a constant velocity due to air resistance.

True

If the input force of a machine is less than the output force, then the input distance is greater than the output distance.

True

A fixed pulley is an example of a compound machine.

False

The force exerted by the tab to open a soda can is greater than the force applied by the person to the tab.

True

A screwdriver is an example of a lever.

True

A wheel chair ramp is an example of an inclined plane.

True

A nutcracker is an example of a wedge.

True

The force required to push a full shopping cart is less than the force required to push an empty one due to Newton's third law.

False

The acceleration of a 0.2 kg baseball thrown with a force of 30N is 150 m/s^2.

True

A WWF wrestler with a mass of 157 kg weighs approximately 1550 N.

True

The momentum of a 4.7 g bullet shot from a gun at 1600 m/s is greater than the momentum of a baseball with a mass of 150g thrown at 39m/s.

True

The reaction force in a balloon car is the force exerted by the air molecules on the balloon.

True

Bernoulli's principle states that the pressure of a fluid decreases as its velocity increases.

True

The buoyancy force on an object is equal to its weight when it is suspended.

True

## Study Notes

### Physics Exam Study Guide

### Terms and Concepts

- Vector vs Scalar Quantity:
- Vector: has magnitude and direction
- Scalar: has only magnitude

- Motion:
- Frame of Reference: a fixed point from which motion is measured

- Distance vs Displacement:
- Distance: total length of path traveled
- Displacement: shortest distance between initial and final positions

- Speed vs Velocity:
- Speed: scalar quantity, rate of change of distance
- Velocity: vector quantity, rate of change of displacement

- Instantaneous Speed vs Average Speed:
- Instantaneous Speed: speed at a specific point in time
- Average Speed: total distance traveled divided by time

- Distance vs Time Graphs:
- Slope of the graph represents velocity

- Acceleration:
- Rate of change of velocity
- Can be calculated using the formula: a = Δv / Δt

- Velocity vs Time Graphs:
- Slope of the graph represents acceleration

- Force:
- Push or pull that causes an object to change its motion

- Newton's Laws of Motion:
- First Law: Inertia, an object at rest stays at rest, an object in motion stays in motion
- Second Law: F = ma, force is equal to mass times acceleration
- Third Law: Every action has an equal and opposite reaction

- Work and Energy:
- Work: force applied over a distance
- Energy: ability to do work

- Machines:
- Simple Machines: lever, pulley, wheel and axle, inclined plane, wedge, screw
- Compound Machines: combination of simple machines

- Momentum:
- Product of an object's mass and velocity

- Pressure:
- Force per unit area

- Bernoulli's Principle:
- Faster moving fluids have lower pressure, slower moving fluids have higher pressure

- Buoyancy and Buoyancy Force:
- Upward force exerted on an object by a fluid (liquid or gas)
- Archimedes' Principle: buoyancy force is equal to the weight of the fluid displaced

- Friction:
- Force that opposes motion between two surfaces in contact
- Types: static, sliding, rolling, fluid

### Formulas

- Average Velocity or Speed:
- v_avg = Δx / Δt

- Average Acceleration:
- a_avg = Δv / Δt

- Acceleration:
- a = F / m (Newton's Second Law)

- Weight:
- W = mg (mass times acceleration due to gravity)

- Momentum:
- p = mv (mass times velocity)

- Pressure:
- P = F / A (force per unit area)

- Work:
- W = F × d (force times distance)

- Power:
- P = W / t (work divided by time)

### Review Questions

- Questions 1-44: various physics concepts and problems

Review key physics concepts for 8th grade science exam, including vector and scalar quantities, motion, distance, speed, velocity, acceleration, and graph interpretation.

## Make Your Own Quizzes and Flashcards

Convert your notes into interactive study material.

Get started for free