teas 7 science practice - Nurselytic

Correct Answer: C

Rationale: Work is done on an object whenever a force causes displacement in the object's position. According to the work-energy principle, work is calculated as the force applied multiplied by the distance the object moves in the direction of the force.
Therefore, work can occur whenever there is a force exerted on the object resulting in displacement, regardless of whether the object's velocity changes or it is lifted vertically.
Choice A is incorrect because work can be done even without a change in velocity.
Choice B is incorrect as work requires both force and displacement, not just the application of force.
Choice D is incorrect because work is not limited to vertical lifting; it can happen in any direction as long as there is a force causing displacement.

Correct Answer: B

Rationale: When the angle between the force and displacement is 90 degrees, the work done is given by the formula W = F * d * cos(theta), where theta is the angle between the force and displacement vectors. Since cos(90 degrees) = 0, the work done becomes zero. This means that no work is done on the object when the angle between the force and displacement is 90 degrees.
Choice A is incorrect because maximum work is done when the force and displacement are in the same direction (theta = 0 degrees).
Choice C is incorrect as minimum work is done when the force and displacement are parallel (theta = 0 degrees), not perpendicular.
Choice D is incorrect because work cannot be infinite; it depends on the force, displacement, and the cosine of the angle between them.

Correct Answer: A

Rationale: Velocity is a vector quantity that describes the speed of an object along with its direction of motion. Unlike speed, which is a scalar quantity focusing solely on the magnitude of motion, velocity considers both speed and direction.
Therefore, the best definition of velocity is 'speed in a specific direction.'
Choice B, 'Distance traveled in a given time,' is incorrect as it defines speed rather than velocity.
Choice C, 'Rate of change of position,' is more aligned with the definition of velocity but lacks the specificity of direction.
Choice D, 'Acceleration due to gravity,' is unrelated to the definition of velocity and refers to a different concept in physics.

Correct Answer: A

Rationale: Solutions with a pH less than 7 are classified as acidic. pH values below 7 indicate an acidic solution, which means it has a higher concentration of hydrogen ions.

Choices B, C, and D are incorrect as they describe neutral (pH 7), alkaline (pH greater than 7), and basic (another term for alkaline), respectively, which are not applicable to solutions with a pH less than 7.

Correct Answer: B

Rationale: The main organ responsible for producing enzymes is the pancreas. Enzymes are proteins that act as biological catalysts to speed up chemical reactions in the body. The pancreas produces and releases digestive enzymes that help break down carbohydrates, proteins, and fats in the small intestine to aid in the digestion and absorption of nutrients. While the liver also plays a role in producing bile, which helps in the digestion and absorption of fats, the primary organ responsible for producing enzymes is the pancreas. The stomach produces gastric juices containing hydrochloric acid and pepsin to help break down food, but it is not the primary organ for enzyme production. The small intestine is where most nutrient digestion and absorption occur; however, it receives enzymes from organs like the pancreas rather than producing them itself.