1. Sweat glands help regulate body temperature by:

A. Producing sebum for lubrication
B. Constricting blood vessels in the skin (sweating doesn't cause constriction)
C. Releasing a watery fluid that evaporates for cooling
D. Thickening the epidermis for insulation

Correct answer: C

Rationale: The correct answer is C. Sweat glands help regulate body temperature by releasing a watery fluid that evaporates for cooling. When the body temperature rises, sweat glands produce sweat, which is mostly composed of water and salts. As this sweat evaporates from the skin's surface, it absorbs heat energy from the body, thus cooling it down. This process is essential for maintaining a stable body temperature during physical exertion or exposure to heat. Options A, B, and D are incorrect as sebum produced by sebaceous glands lubricates the skin, blood vessels dilate rather than constrict during sweating to release heat, and the epidermis does not thicken for insulation related to sweat glands.

2. What property of a wave is measured in Hertz (Hz)?

A. Amplitude
B. Wavelength
C. Speed
D. Frequency

Correct answer: d

Rationale: Frequency, the number of oscillations per second, is measured in Hertz (Hz).

3. In a chemical reaction, the total amount of:

A. Matter remains the same
B. Matter increases
C. Matter decreases
D. Energy remains the same

Correct answer: A

Rationale: The Law of Conservation of Mass states that matter cannot be created or destroyed in a chemical reaction, only rearranged

4. The part of the brain responsible for balance and coordination is the:

A. Cerebellum
B. Cerebrum
C. Hypothalamus
D. Thalamus

Correct answer: A

Rationale: The correct answer is A: Cerebellum. The cerebellum is the part of the brain responsible for balance and coordination. It receives information from the sensory systems, spinal cord, and other parts of the brain to coordinate voluntary movements such as posture, balance, and speech. The cerebrum (option B) is responsible for higher brain functions such as thinking and decision-making. The hypothalamus (option C) is involved in regulating basic biological needs such as hunger and thirst. The thalamus (option D) acts as a relay station for sensory information. Therefore, the cerebellum is the specific part of the brain that plays a crucial role in maintaining balance and coordination.

5. What is the work done by a force of 20 N acting on an object that moves 5 meters in the direction of the force?

A. 100 Joules (J)
B. 25 Joules (J)
C. 4 Joules (J)
D. Work cannot be determined without knowing the object's mass.

Correct answer: A

Rationale: Work is defined as the force applied multiplied by the distance moved in the direction of the force. Work = force x distance = 20 N x 5 m = 100 J.

6. How does the mass of an object affect its inertia?

A. Mass has no impact on inertia
B. Higher mass increases inertia
C. Higher mass decreases inertia
D. Mass influences gravitational force, not inertia

Correct answer: B

Rationale: Inertia is the resistance of an object to changes in its state of motion. The greater the mass of an object, the greater its inertia because it requires more force to change its state of motion. This is in line with Newton's first law of motion, which states that an object at rest will stay at rest, and an object in motion will stay in motion with the same speed and in the same direction unless acted upon by an external force.