WorksheetsScience Field
Total questions: 10
Worksheet time: 12mins
Mercury-in-glass thermometers work on the principle of volumetric expansion, which is that most materials expand as they get warmer. A common glass thermometer contains liquid mercury that rises upward in a glass tube as the temperature of
the thermometer increases.
The liquid moves up the tube for which of the following reasons?
Only the glass contracts as its temperature decreases, so the liquid mercury moves up the tube to occupy more of the tube’s internal space.
While both the glass and the liquid mercury contract as their temperatures increase, the glass contracts more rapidly than the mercury does.
The pressure of gas above the liquid mercury decreases as its temperature rises, and the liquid mercury is sucked upward in the glass tube.
While both the glass and the liquid mercury expand as their temperatures increase, the liquid mercury expands more rapidly than the glass does.
Homeostasis refers to the ability of cells or body systems to keep a stable internal environment as the external environment changes. Cells and body systems monitor their internal environment and adjust the internal conditions if a change occurs. These adjustments may be made through a negative feedback system.
A negative feedback system is a process in which an initial change will bring about an additional change in the opposite direction.
A positive feedback system is a process in which an initial change will bring about an additional change in the same direction. Positive feedback does not maintain homeostasis.
Which of the following is NOT an example of a negative feedback system?
A person is hungry for a long time, so that person’s body metabolism slows down, allowing the body to survive on less food.
The kidneys detect a decrease of oxygen in the blood, so they secrete a hormone called erythropoietin that increases the production of red blood cells.
Blood pressure increases, so the brain signals the heart to slow down its rate, thus reducing the pressure.
Proteins are only partially digested, so the digestive system secretes hydrochloric acid and pepsin, speeding up the process.
Heat from a hot cooking pot moves to the pot handle by
• Conduction–The transfer of heat or thermal energy by diffusion and collisions of particles within a substance due to a temperature gradient. By this process, heat is transferred through one substance to another when the two substances are in direct contact. For example, heat is transferred to a metal pot placed on a hot burner.
• Convection–The transfer of heat from one place to another by the movement of fluids. For example, when air heats up, the particles move farther apart and become less dense, causing the heated air to rise.
• Thermal radiation–The transfer of heat by radiation generated by the motion of charged particles. This method of heat transfer does not rely on any contact between the heat source and the heated object. For example, a person’s face is warmed by light radiated from the sun.
Conduction
Convection
Radiation
Both convection and radiation
Both conduction and convection
According to the law of conservation of energy, energy can neither be created nor be destroyed, only transferred and transformed from one form to another. What kind of energy conversion is taking place when an electric bread toaster is switched on?
Chemical → Electrical
Electrical → Thermal
Electrical → Sound
Electrical → Chemical
What is the acceleration of a car with a mass of 1,000 kg if the driving force is 3,600 N and the friction/air resistance is 800 N?
Newton’s second law states that the acceleration of an object is dependent on the object’s
mass and the amount of force applied on the object. Therefore, acceleration (a) = force (F) / mass (m)
Acceleration (a) is the rate of change of velocity (v) of an object. Therefore,
The unit of acceleration is m/s2. The unit of force is newton (N) and 1 newton = kg (m/s2). Any object usually has more than one force acting on it at any time (e.g., driving force, air resistance, and friction). If two forces are acting in the opposite direction, then the difference between those two forces gives the resultant force.
2.8 m/s2
28 m/s2
3.6 m/s2
0.8 m/s2
Iron (Fe) has an atomic number of 26 and an atomic mass of 56. Which of the following correctly describes the nucleus of an iron atom?
Per Newton’s second law, force = mass × acceleration (a)
2,800 N = 1,000 kg × a
a = 2,800 N/1,000 kg = 2.8 m/s2
An atom is the smallest possible particle of a substance and is made up of three particles: protons, electrons, and neutrons.
• Protons have a positive charge, “+”.
• Electrons have a negative charge, “−”.
• Neutrons do not have a charge at all. They are electrically neutral.
The atomic mass of an element is the total of the number of protons and neutrons. The atomic number is equal to the number of protons in the nucleus of an atom and determines the identity of the element.
26 protons ,30 neutrons
26 protons, 56 neutrons
56 protons, 56 neutrons
30 protons, 26 neutrons
Mutation is a change in a chromosome that in some way alters the genetic message conveyed by that gene. Which of the following is a likely outcome of a mutation?
Alternation in the number of chromosomes of the gene
Change in the life span of the organism
Change in the physical appearance of the organism
Increased rate of cell divison
Mountains are formed when tectonic plates lift and tilt over as a result of grinding against each other. These gigantic movements and shifts cause collision and crumpling of Earth’s crust and, in turn, form mountains. Which of the following is NOT a cause of mountain formation?
Tectonic plate shifts
Volcanic action
Global warming
Tectonic plate collisions
In humans, dark hair color, D, is dominant over light hair color, d. If the egg cell of a blonde female who carries only the genes for light colored hair, dd, is fertilized by the sperm cell of a male who carries only the genes for dark hair, DD, what are the chances that the offspring will have dark hair?
100 percent
50 percent
25 percent
Zero percent
The wave equation states the mathematical relationship between the speed (v) of a wave and its wavelength (λ) and frequency (f).
Speed = wavelength x frequency
A sound source sends waves of 400 Hz. It produces waves of wavelength 2.5 m. The velocity of the sound waves is
100 m/s
1,000 m/s
10,000 m/s
3,000 m/s
