what does the term net force refer to in physics

ATI TEAS 7

TEAS 7 science quizlet

1. In physics, what does the term 'net force' refer to?

A. Total force acting on an object
B. Force due to gravity
C. Force in motion
D. Force of friction

Correct answer: A

Rationale: In physics, the term 'net force' refers to the total force acting on an object, considering all individual forces acting on it. It is crucial in determining the object's motion and acceleration as it represents the overall force applied to the object. Choice B, 'Force due to gravity,' is incorrect as it refers to a specific force acting on an object due to gravity. Choice C, 'Force in motion,' is incorrect as it does not define the concept of net force. Choice D, 'Force of friction,' is incorrect as it specifically refers to the force opposing motion when two surfaces are in contact.

2. What is the definition of power in physics?

A. The rate of change of energy
B. The rate of doing work or transferring energy
C. The measure of an object's potential energy
D. The force exerted on an object

Correct answer: B

Rationale: The correct answer is B: 'The rate of doing work or transferring energy.' Power in physics is defined as the rate at which work is done or energy is transferred. It is a measure of how quickly energy is transferred or converted. Power is not the same as energy itself but rather how fast energy is being transferred or converted. Choice A, 'The rate of change of energy,' is incorrect because power is about the rate of work or energy transfer, not just the change in energy. Choice C, 'The measure of an object's potential energy,' is incorrect as power is not a measure of potential energy but rather the rate of energy transfer. Choice D, 'The force exerted on an object,' is incorrect as power is related to work and energy transfer, not just force exerted.

3. Which type of wave does not require a medium for propagation?

A. Transverse wave
B. Longitudinal wave
C. Mechanical wave
D. Electromagnetic wave

Correct answer: D

Rationale: The correct answer is D, Electromagnetic wave. Electromagnetic waves do not require a medium for propagation because they consist of oscillating electric and magnetic fields that can travel through a vacuum. In contrast, transverse and longitudinal waves are mechanical waves that require a medium (solid, liquid, or gas) for propagation. Therefore, options A, B, and C are incorrect as they are all types of mechanical waves that necessitate a medium for transmission.

4. What is the difference between a pure substance and a mixture?

A. Pure substances have a fixed composition, mixtures don't.
B. Mixtures have a fixed composition, pure substances don't.
C. Pure substances can be in any state, mixtures are not always solids.
D. Pure substances are always elements, mixtures are always compounds.

Correct answer: A

Rationale: Pure substances have a definite and constant composition, meaning they are made up of only one type of atom or molecule with fixed proportions. This composition does not vary. On the other hand, mixtures are composed of two or more substances physically combined. The components of a mixture can be present in varying proportions, leading to a variable composition. Choice A is correct as it accurately distinguishes between pure substances and mixtures based on the fixed composition of pure substances and the variable composition of mixtures. Choice B is incorrect because mixtures, not pure substances, have variable compositions. Choice C is incorrect as both pure substances and mixtures can exist in different states. Choice D is incorrect because pure substances can be compounds as well, not exclusively elements, and mixtures can contain elements and compounds.

5. Which of the following neurotransmitters slows down the activity of neurons to prevent overexcitation?

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

Correct answer: C

Rationale: The correct answer is C: GABA (gamma-aminobutyric acid). GABA is an inhibitory neurotransmitter that slows down neuronal activity, helping to prevent overexcitation in the brain. It counterbalances the effects of excitatory neurotransmitters like glutamate, playing a crucial role in maintaining the balance of neuronal activity in the brain. Acetylcholine (Choice A) is primarily an excitatory neurotransmitter involved in muscle movement and cognitive functions. Dopamine (Choice B) plays a role in reward-motivated behavior and motor control. Serotonin (Choice D) is involved in regulating mood, appetite, and sleep but is not primarily responsible for slowing down neuronal activity to prevent overexcitation.