how does the acceleration of an object change if the force acting on it is doubled

ATI TEAS 7

ati teas 7 science

1. How does the acceleration of an object change if the force acting on it is doubled?

A. Acceleration is halved
B. Acceleration doubles
C. Acceleration remains unchanged
D. Acceleration quadruples

Correct answer: B

Rationale: According to Newton's second law of motion, acceleration is directly proportional to the force acting on an object. When the force acting on an object is doubled, the acceleration of the object will also double. This relationship is described by the formula F = ma, where F is the force applied, m is the mass of the object, and a is the acceleration. Therefore, an increase in force will result in a proportional increase in acceleration. Choice A is incorrect because acceleration does not halve but doubles when force doubles. Choice C is incorrect as acceleration changes in direct proportion to force. Choice D is incorrect as acceleration does not quadruple but doubles when force doubles.

2. Which term describes the resistance of a substance to flow?

A. Density
B. Viscosity
C. Conductivity
D. Malleability

Correct answer: B

Rationale: Viscosity is the term used to describe the resistance of a substance to flow. It quantifies how thick or thin a fluid is and how easily it flows. Density (A) refers to the mass of a substance per unit volume and does not directly relate to resistance to flow. Conductivity (C) is the property of a material to conduct electricity or heat, not related to resistance to flow. Malleability (D) is the property of a material to be hammered or rolled into thin sheets, which is not related to resistance to flow.

3. Which neurotransmitter is involved in muscle movement?

A. Dopamine
B. Acetylcholine
C. Serotonin
D. GABA

Correct answer: B

Rationale: Acetylcholine is the neurotransmitter responsible for muscle movement. It is released from motor neurons at the neuromuscular junction and binds to receptors on muscle fibers, initiating muscle contraction. Dopamine, serotonin, and GABA serve different functions in the brain and body, such as regulating mood, sleep, and inhibitory signaling, respectively. Therefore, choices A, C, and D are incorrect in the context of muscle movement.

4. Which statement is true regarding the process of digestion?

A. Digestion of starch begins in the mouth.
B. Amylase is produced by the stomach to help break down food in the upper intestine.
C. The di- and tri-saccharides produced in early digestion are absorbed through the intestinal wall.
D. Proteases are responsible for breaking down starches.

Correct answer: A

Rationale: The statement 'Digestion of starch begins in the mouth' is correct. Salivary amylase, an enzyme produced in the salivary glands, initiates the breakdown of starch into simpler sugars like maltose in the mouth before further digestion in the stomach. This initial breakdown of starch is crucial in the digestion of carbohydrates, marking the beginning of the digestive process. Choice B is incorrect because amylase is produced in the salivary glands, not the stomach. Choice C is incorrect because di- and tri-saccharides are further broken down into monosaccharides before absorption. Choice D is incorrect because proteases are enzymes that break down proteins, not starches.

5. The Minimum Inhibitory Concentration (MIC) of an antibiotic refers to:

A. The lowest concentration that kills bacteria
B. The dose required for 50% bacterial inhibition
C. The time it takes for an antibiotic to work
D. The spectrum of bacteria the antibiotic targets

Correct answer: B

Rationale: A) The lowest concentration that kills bacteria is known as the Minimum Bactericidal Concentration (MBC), not the Minimum Inhibitory Concentration (MIC). MIC is the lowest concentration of an antibiotic that inhibits visible growth of bacteria. B) The MIC of an antibiotic is the concentration at which bacterial growth is inhibited by 50%. This concentration is used to determine the effectiveness of an antibiotic against a specific bacterium. C) The time it takes for an antibiotic to work is not described by the MIC. MIC is a measure of concentration, not time. D) The spectrum of bacteria the antibiotic targets is not defined by the MIC. The MIC value is specific to a particular antibiotic and bacterium, regardless of the spectrum of activity of the antibiotic.