Physics Motion Quiz 02

The approximate mass of a high school student (in kilograms) is:

• 1

• 5

• 65

• 250

The approximate length of a baseball bat is:

• 1 mm

• 1 cm

• 1 m

• 1 km

A friend claims that he can measure exactly how much water is in a one-gallon jug after taking a drink from it. You disagree with your friend. Which of the following reason would a scientist give for agreeing with you?

• All measurements contain random errors.

• A perfect measurement requires scientific expertise, which your friend does not have.

• A perfect measurement requires a very expensive instrument, which your friend cannot afford.

Three students measure the length of their classroom and get the following values:

Student A – 6.54 m Student B – 6.57 m Student C – 6.52 m

Because all three students received three different measurements, this is an example of:

• a random error.

• an operator error.

• a systematic error.

• a predictable error.

Students in a class measure their stride, and use that measurement to determine the length of a school’s soccer field. As a result, each group arrives at a different value for the length of the field. The way to achieve the most accurate value for the length of the field would be to:

• get the class to agree on using one group’s value.

• pick the highest and the lowest values and average them.

• have everyone measure again, and then find out which number is repeated.

• average all the values of each group.

A friend measures the length of the school soccer field to be sure that it is the correct size. Which measuring device will most likely help your friend get the most accurate answer?

• A meter stick accurate to the nearest mm.

• A 30-cm ruler accurate to the nearest mm.

• A 50-m tape measure accurate to the nearest cm.

• A meter stick accurate to the nearest cm.

What is the best measuring tool for measuring the length of a hallway and why?

• A meter stick because it is more accurate.

• A tape measure because you can take fewer measurements.

• A tape measure because it uses standard American units.

• A meter stick because it uses SI units.

You are driving on a highway that that posts a 65 mph speed limit. Your speedometer is accurate within 5 mph. What is the maximum reading your speedometer can give that you will be sure is not over the speed limit? (Give the number without units.)

Tags

NGSS.MS-PS2-2

What is the difference between accuracy and precision?

• They mean pretty much the same thing.

• Accuracy is being close to a known value; precision is having multiple results that are similar.

• Accuracy is getting the same result over and over; precision is being right.

• Accuracy is having multiple results that are similar; precision is being close to a known value.

A:  Two students measure the same length and obtain values of 3 meters and 10 meters.

B:  Two students measure the same length and obtain values of 3 meters and 3.01 meters.

Why are there differences in the measured values?

• In A there is a systematic error; in B there is a random error.

• In A there is a random error; in B there is a systematic error.

• In A there is a random error; in B there is an operator error.

• In A there is an operator error; in B there is a systematic error.

• In A there is an operator error; in B there is a random error.