Deck 1: Physics and the Life Sciences

Question 1

The largest blue whale ever measured weighed around 420000 pounds (lb). The SI unit for weight is the newton (N), and one pound (1 lb) 4.5 N. Which of the following values represents the mass of the whale in SI units? Note: weight = mass × g, where g = 9.8 m/s².

A)1.9 ×10⁵g
B)1.9 ×10⁵ kg
C)1.9 ×10⁷g
D)1.9 ×10⁷ kg

Answer 1

1.9 ×10⁵ kg

Question 2

How many significant figures are in 20006?

A)2
B)3
C)4
D)5

Answer 2

5

Question 3

Which of the following is the value for (6.28 ÷ 0.21 × 1125), with the correct number of significant figures?

A)33640
B)33642.871428
C)33643
D)34000

Answer 3

34000

Question 4

When creating a model to explain a certain physical concept, what are observations and collected data most useful for?

A)making predictions
B)proving that the model is correct without a doubt
C)testing predictions made by the model
D)generating catalogues

Question 5

How many significant figures are in 0.0235?

A)2
B)3
C)4
D)5

Question 6

The principle of Occam's razor is a principle of reasoning; what does it say we should generally do?

A)Prefer simpler or more parsimonious explanations to the more complicated ones.
B)Reason from detailed particular observations to general or universal principles.
C)Accept nothing as true without compelling empirical or mathematical evidence of its truth.
D)Reason from general or universal principles to particular results.

Question 7

Exploring proportions in the human body, you can notice that the span of your arms is equal to your body height. If a child has height of 1.3 m, and an adult 1.74 m, by approximately what factor is the adult's arm length longer than that of the child?

A)1.34
B)1.55
C)1.79
D)2.40

Question 8

Which of the following numbers is the value for (536.0 + 0.7341), with the correct number of significant figures?

A)536.7341
B)536.734
C)536.73
D)536.7

Question 9

Total lung capacity of a male, on average, is about 6 L of air. What would this be when expressed in cubic metres?

A)6 m³
B)6 ×10^-3 m³
C)6 × 10^-6 m³
D)This cannot be done.The dimensions are different.

Question 10

The thickness of human hair is around 100 micrometres (ìm). If a width of a DNA molecule is around 10 nanometres (nm), how many DNA molecules can fit across a hair strand?

A)10²
B)10³
C)10⁴
D)10⁵

Question 11

Which of the following numbers has the highest precision?

A)6 × 10^-8 m³
B)1.200008
C)12.534
D)2.38675 × 10⁹ m³

Question 12

The flow rate of a fluid is expressed as a velocity of fluid multiplied by the cross-sectional area of the pipe (vA). Assume that the pipe is a blood vessel with circular cross-sectional area calculated as A = ðr², where r is radius. In a continuous flow rate, where v₁A₁ = v₂A₂, what is the change of the velocity of blood if a blood vessel with radius r₁ reduced its radius by a factor of 2 to r₂ = r₁/2?

A)v₂ = (1/4)v₁
B)v₂ = 2v₁
C)v₂ = 4v₁
D)v₂ = (1/2)v₁

Question 13

Which of the following units is a fundamental unit in the SI?

A)kilometre (km)
B)kilogram (kg)
C)gram (g)
D)newton (N)

Question 14

Which of the following relationships is dimensionally consistent? In these equations, a is acceleration, v is velocity, t is time, and x is distance.

A)a = v/t²
B)a = v/x²
C)a = v²/t
D)a = v²/x

Question 15

Which of the following is the value for the product of (1.362 × 10⁵)(8.5 × 10⁶), with the correct number of significant figures?

A)1.1577 × 10¹²
B)1.158 × 10¹²
C)1.16 × 10¹²
D)1.2 × 10¹²

Question 16

Which of the following measurements has the highest precision?

A)the height of the classroom wall (around 300 cm) with uncertainty of 3 cm
B)the depth of a canyon (around 1800 m) with uncertainty of 15 m
C)the thickness of human hair (0.0001 m) with uncertainty of 0.00003 m
D)the mass of 1 kg with the uncertainty of 0.005 g

Question 17

If an adult has 3 times the weight of a child, the adult's foot will be twice as long and twice as wide as the child's foot. What is the ratio of force per unit area (pressure P) exerted on the feet of the child compared to the force exerted on the adult's feet?

A)1/3
B)3/4
C)4/3
D)3

Question 18

Which of the following relationships is dimensionally consistent? In these equations, a is acceleration, v is velocity, t is time, and x is distance.

A)x = v²/a
B)x = at/v
C)x = v/t
D)x = a²/v

Question 19

To convert a quantity from m/s² to km/hr/s, what must you do?

A)multiply by 1000 and divide by 60
B)multiply by 1000 and divide by 3600
C)multiply by 60 and divide by 1000
D)multiply by 3600 and divide by 1000

Question 20

In the expression where x has units metre (m), and v_f and v₀ have units m/s, what are the units for P?

A)m/s
B)m
C)m/s²
D)no units

Question 21

Hooke's law for restoring the force of an oscillating system is F = -kx. If F is a force (unit N) and x is displacement (unit m), then the unit of the constant k is kg m²/s².

Question 22

Any of the following numbers is a correct way to write 96300000 in scientific notation: 963 × 10⁵, 96.3 × 10⁶, or 9.63 × 10⁷.

Question 23

A cylindrical water tank holds 650 L of water. The volume of a cylinder is given by V = ðr²h (r is radius, h is height). How much water (in litres) could the tank hold if the radius was doubled and the height reduced to half?

Question 24

You are measuring your weight on a scale.
(a) You are measuring your weight on a digital scale which can even show one decimal. The measurement shows 120.7 lb. Within what limits is your true weight likely to be?
(b) You are measuring your weight on another type of scale that has a known uncertainty of ±0.5 lb and shows 121 lb. Within what limits is your true weight likely to be?

Question 25

Estimate the number of hairs on your head, if you counted 50 hairs on a 5 mm × 5 mm area. State your assumptions.

Question 26

Radioactive decay is described with the following law: N = N₀ × 2^-ët, where N is the number of nuclei, N₀ is the original number of nuclei at the start of the process, t is time needed for N0 to decay to N, and ë is a radioactive constant of a particular element. What are the units of ë? If the radioactive constant of another element is larger, does that element require a shorter or longer time to perform the same decay?

Question 27

Numbers 0.025 and 25 have the same number of significant figures.

Question 28

Some astrologers claim that the gravitational influence of Mars can affect a child during birth. Gravitational force is linearly proportional to the masses of two bodies and decreases with the square of the distance between those bodies. Compare the influence of Mars (at a distance is 7.8 × 10⁷ km from Earth) and a 70 kg doctor at a distance of 0.1 m, on a 3 kg baby. The mass of Mars is 6.42 × 10²³ kg, and the universal gravitational constant is G = 6.67300 × 10^-11 m³ kg^-1s^-2.

Question 29

The masses of the human brain and body are related as mass_brain is proportional to (mass_body)^0.68. Find the brain mass of a dolphin:
(a) if we assume that the dolphin is as intelligent as a human, and
(b) if we assume that it is as intelligent as a chimpanzee. Compare your results to the real value from the table and draw a conclusion about its intelligence ranking.

Question 30

Nerve fibres conduct impulses with a speed of 72 m/s in rats, which is faster than the 72 km/h speed of conduction in squids.

Question 31

When choosing between two models that explain a physical principle with equal success, but differ in complexity of the explanation, how do we choose the more plausible model?

Question 32

Calculate both the sum of and the difference between the following two numbers: 1.04 × 10^-5 m and 7.7 × 10^-7 m. Express your results using correct units, number of significant digits, and scientific notation.

Question 33

Numbers 20 and 20.0 have the same number of significant figures.

Question 34

Earth's equator, with a circumference of around 40000 km, is longer than the total length of capillaries in the human body (6 × 10⁹ cm).

Question 35

Average human heartbeat is 75/minute. How many heartbeats has a 20-year-old student had since birth?

Question 36

In creating a model that would explain a certain physical concept, observations and collected data are most useful for proving that the model is a true representation of a concept.

Question 37

The speed of light is 3 × 10⁸ m/s. The distance between Earth and the Sun is roughly 150 million kilometres. How long does it take for light to travel from the Sun to Earth? Express the result in seconds, minutes, hours, and days. Which unit is most appropriate?

Question 38

When adding or subtracting numbers, the result has the same precision as the least precise number used in the calculation.

Question 39

The calculator can hold only a few significant digits. When adding a set of positive numbers of widely varying magnitude on a calculator, in order to get the result with the highest precision, one should start at the largest number and add successively smaller ones.

Question 40

The smallest power of 10 quoted in a result is a good indicator of the precision of the measurement.