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

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.

Correct Answer: D

Rationale: A scalar quantity is a physical quantity that has magnitude only, without any direction. Speed is an example of a scalar quantity because it only describes how fast an object is moving without specifying the direction of motion. Velocity, acceleration, and force are vector quantities because they have both magnitude and direction. Therefore, the correct answer is 'Speed.' Choices A, B, and C are incorrect because velocity, acceleration, and force are all vector quantities that involve both magnitude and direction.

Correct Answer: C

Rationale: When an object moves through a fluid, it experiences resistance due to the viscosity of the fluid. This resistance is known as the viscous force, which opposes the motion of the object. Gravitational force is the force of attraction between two objects with mass, tension force is the force transmitted through a string, and magnetic force is the force exerted by magnets. In the context of an object moving through a fluid, the force opposing its motion is the viscous force because it resists the relative motion of the object through the fluid.

Correct Answer: A

Rationale: Work is defined as the product of the force applied to an object and the distance over which the force is applied. The formula to calculate work is represented by Work = Force Distance, where force is the applied force on an object and distance is the displacement over which the force is applied. Therefore, the correct formula to calculate work is Work = Force Distance. Choice B, 'Work = Mass Velocity,' is incorrect because work involves force and distance, not mass and velocity. Choice C, 'Work = Power Time,' is incorrect because work is not directly calculated using power and time. Choice D, 'Work = Energy · Time,' is incorrect because work is not typically calculated by dividing energy by time; rather, it involves the product of force and distance.

Correct Answer: B

Rationale: - Genotype refers to the genetic makeup of an organism, including all the genes and alleles it possesses. - Phenotype, on the other hand, refers to the observable physical characteristics or traits of an organism, which result from the interaction between its genotype and the environment. - While genotype represents the genetic potential or range of traits that an organism can express, phenotype reflects the actual expression of specific traits. - Therefore, option B correctly captures the distinction between genotype and phenotype in the context of gene expression.