Explanation

Explanation

The force of friction always acts opposite to the direction of the applied force or intended motion.

It resists relative motion between surfaces.

Explanation

The SI unit of acceleration is meters/second^2 (m/s^2 or ms^-2)

Acceleration (a) is defined as the rate of change of velocity.

Velocity is a vector quantity, and therefore acceleration is also a vector quantity.

Explanation

Multiplying a vector by a negative number (scalar) reverses its direction.

Example: If $\vec{v}$ has direction, then $-k\vec{v}$ (where $k>0$) points opposite to $\vec{v}$.

Explanation

The centimeter (cm) is a metric unit of length or distance. 

It is equal to 0.01 meters.

Explanation

Physics is the branch of science that studies the properties of matter, energy, and their interactions.

It encompasses mechanics, thermodynamics, electromagnetism, and more.

Explanation

pH stands for "Potential Hydrogen"

Blood is normally slightly basic, with a normal pH range of about 7.35 to 7.45.

Usually, the body maintains the pH of blood close to 7.40.

Acidosis is characterized by a pH of 7.35 or lower. Alkalosis is characterized by a pH level of 7.45 or higher.

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Explanation

Conductance (the ability to conduct electricity) generally increases with temperature for electrolytes (e.g., ionic solutions).

Because higher temperature enhances ion mobility and dissociation.

Explanation

In HNO₃ (nitric acid):

Hydrogen (H) = +1

Oxygen (O) = -2 (×3 = -6)

Let nitrogen = x

So, +1 + x + (−6) = 0

⇒ x = +5

Nitrogen has an oxidation state of +5 in HNO₃.

Explanation

Formalin (a solution of formaldehyde gas in water, typically 37-40%) is widely used as a preservative for biological specimens (e.g., in museums, labs, and medical settings).

It fixes tissues by cross-linking proteins, preventing decay and maintaining structure.