1.
The SI unit for electric current is the __________
Correct Answer
D. Ampere
Explanation
The SI unit for current is the ampere
2.
The SI unit for amount is the __________
Correct Answer
A. Mole
Explanation
The mole is the official SI unit for amount. It is a big number. Note that it is not the SI unit for mass, that is the gram.
3.
1.2 milliseconds = _____________ minutes.
Correct Answer
A.
4.
The human population on earth currently is approximately 7,125,000,000 people. Using scientific notation with the correct number of significant figures, this is ________________________________ people
Correct Answer
A.
Explanation
note only four significant figures since there is no decimal place. And note that this is about 7 billion people, not 7 trillion To convert to scientific notation make your number between 1 and 10 by drawing a line, then count the placeholders to the decimal point: 7|125 000 000. =
5.
Aluminum has a density of 2.70 g/mL and zinc has a density of 7.13 g/ml. Therefore 10.0 g of zinc combined with 10.0 g of aluminum has a total volume of _______ L. (Be sure to give the total volume in liters, not milliliters).
Correct Answer
B. .00511
Explanation
10 g x 1 mL/2.70 g + 10 g x 1 mL/7.13 mL = 5.106 mL = .005106 L; 3 SF so .00511 L
6.
The volume of 1.24 pounds of aluminum is __________ cubic inches. (453.6 grams = one pound, density of Al = 2.70 g/cm3, 1.00 cubic inch = 16.39 cubic centimeters). suggestion: convert from pounds to grams to cubic centimeters then to cubic inches. Use scrap paper and make sure all your units cancel.
Correct Answer
A. 12.7
7.
In a mentos eruption experiment the measured eruption heights in three trials are 6.9, 6.71, and 7.25 bricks. What is the average height of the eruption in centimeters? Please report your answer using three significant figures. (1 brick = 6.50 cm)suggestion: take the average by adding up the data and dividing by exactly three. Consider how precise your answer should be.
Correct Answer
E. 45.2 centimeters
8.
If I travel at 60.2 miles per hour for 17.13 hours, then double my speed to 120.4 miles per hour for 4.00 hours, how many kilometers will I have traveled? (1609 meters = 1 mile)suggestion: calculate each distance in miles, combine them, then convert to meters. Use scrap paper and do it out.
Correct Answer
A.
9.
A balloon of helium with a volume of 22.40 milliliters contains 4.03 milligrams of helium. Based on this data, what is the density of helium? Please be sure to include your units using grams per millliter
Correct Answer
D.
Explanation
The density of a substance is calculated by dividing the mass of the substance by its volume. In this case, the mass of the helium is given as 4.03 milligrams and the volume is given as 22.40 milliliters. To convert milligrams to grams, we divide by 1000. So, the mass of the helium is 0.00403 grams. Therefore, the density of helium is 0.00403 grams divided by 22.40 milliliters, which equals 0.180 grams per milliliter.
10.
Correct Answer
B.
11.
What is the length of the object below, assuming the ruler is based on centimeters? Be sure to answer with the correct level of precision.
Correct Answer
C. 1.35 cm
Explanation
The length of the object below is 1.35 cm because it is the only option that matches the given ruler precision of centimeters. The other options have either more or less precision than the given ruler.
12.
Which measurement uses proper S.I. Units?
Correct Answer
D. 3 meters
Explanation
meters is the SI unit for distance, but all the others are not SI units. Feet should be meters, parsecs should be meters, ounces should be grams, or if you are really picky, kilograms.
13.
Give the number of significant figures in the number 60,402,000
Correct Answer
B. 5
Explanation
Leading zeros only tell where the significant figures are in relation to the decimal point, and therefore are insignificant.
14.
If I have 12 g of grass and it takes up 30 cubic centimeters, what is the density of the grass?
Correct Answer
A. 0.4 g/cubic centimeter
Explanation
The density of a substance is calculated by dividing its mass by its volume. In this question, we are given that the mass of the grass is 12 g and it takes up 30 cubic centimeters of space. To find the density, we divide the mass (12 g) by the volume (30 cubic centimeters), which gives us a density of 0.4 g/cubic centimeter.
15.
Which substance has a higher density?substance a: density = 4.02 milligrams per millilitersubstance b: density = 403 nanograms per microliter
Correct Answer
A. Substance A
Explanation
substance a has a density of 1 gram per liter
but since there are 1000 nanograms in a microgram substance b is less dense.
16.
Solve:
Correct Answer
C. 3.86 x 10^-18 F/B
Explanation
The given expression represents a value in scientific notation, where 3.86 is multiplied by 10 raised to the power of -18. This implies that the value is very small, as it is multiplied by a very small number (10^-18). The unit "F/B" indicates that the value represents a ratio or conversion factor between two quantities, with "F" representing the unit of the numerator and "B" representing the unit of the denominator. Therefore, the answer 3.86 x 10^-18 F/B suggests that the given expression represents a very small conversion factor or ratio between two quantities.
17.
Which one do you like?
Correct Answer
D. 2322000 Foxes/Bear
Explanation
The given options are different choices for what the person likes. The answer "2322000 Foxes/Bear" suggests that the person likes both foxes and bears.
18.
Which one do you like?
Correct Answer
B. If you travel at 3 miles per hour for 14 hours and then travel at 1 mile per second for 3 seconds, how far did you travel?