Chemistry Flash Cards

Chapter 2 chem flash cards

When does distance equal the magnitude of displacement?

A: Only when moving in a straight line without turning back.

Why is a bacterium's distance large but its displacement small?

It moves back and forth repeatedly, ending up close to where it started.

Is a temperature of -5 a vector or scalar

Scalar. The minus sign indicates a point on a scale, not a spatial direction.

Give an example showing the difference between average speed and average velocity magnitude.

Driving one exact lap around a track: your average speed is high, but your average velocity is zero because you ended where you started.

Q10: What do a car’s odometer and speedometer measure?

A: Odometer = distance. Speedometer = instantaneous speed.

Total distance divided by time equals what? When does it equal velocity magnitude?

Average speed. They are only the same if you travel in an unreversed straight line.

How do instantaneous speed and instantaneous velocity differ?

Speed is just the number (how fast); velocity is the number plus the direction.

Speed is just the number (how fast); velocity is the number plus the direction.

Yes, like driving at a steady speed around a sharp curve or circle.

Can velocity be constant if acceleration is not zero?

No. If you accelerate, your speed or direction must change.

Give an example where velocity is zero but acceleration is not

A ball at the exact peak of being thrown straight up.

If a train moving left (negative) comes to a stop, what is its acceleration sign?

Positive (points right to slow it down).

How do you choose which kinematic equation to use?

Match your given variables and your unknown target to the equation missing the variable you don't care about.

What is the last thing you should do when solving a physics problem?

Check the units and see if the final number makes logical sense.

What is the acceleration of a rock thrown straight up, at the top, and on the way down?

It is a constant 9.80m/s² downward the entire time.

Does gravity change signs on the way up versus the way down?

No, gravity always pulls downward.

If gravity on the Moon is 1/6th of Earth's, how much higher can you jump on the moon?

6 times higher.

what is the difference between vector and scalar

A scalar has only a magnitude (a number with units, like temperature or mass). A vector has both a magnitude and a specific spatial direction (like velocity or force).

What does Delta x stand for?

Displacement (how far you are from your starting point).

What does v0 stand for?

Initial velocity (starting speed and direction).

What does v stand for?

Final velocity (ending speed and direction).

What does a stand for?

Acceleration (the rate at which velocity changes).

What does t stand for?

Time interval (how long the motion lasted).

What are the standard metric units for displacement Delta x

Meters

What are the standard metric units for velocity

Meters per second (m/s)

What are the standard metric units for acceleration (a)?

Meters per second squared (m/s^2).

What are the standard metric units for time ($t$)?

Seconds (s)

Which variable is completely missing from Equation 1 (v = v0 + at)?

Displacement (Delta x)

Which variable is completely missing from Equation 3 (Delta x = v0(t) + 1/2at^2)?

Final velocity (v).

Which variable is completely missing from Equation 4 (v^2 = v0^2 + 2aDelta x)?

Time (t)