Explanation

• A stopwatch that measures to 0.1 seconds is typically a mechanical (analog) stopwatch
• The 0.1-second value represents the "least count" of the mechanical instrument
• Digital stopwatches often measure to 0.01s.
• These are commonly used in laboratories for timing experiments. 

Last updated 11-02-2026

Explanation

• The branch of chemistry that studies heat energy released or absorbed during chemical reactions is called Thermochemistry.
• It explains how heat changes occur during reactions such as combustion, neutralization, and dissolution.
• It deals with concepts like enthalpy change (ΔH), exothermic reactions, and endothermic reactions.

Last verified on 11-03-2026

Explanation

• Combustion is a chemical reaction in which a substance reacts rapidly with oxygen to produce heat and light.
• Commonly observed when wood, coal, or fuel burns.
• Combustion is an exothermic reaction because it releases energy.

Last verified on 10-03-2026

Explanation

Explanation

The standard equations of motion for an object moving with uniform (constant) acceleration are

v = u + at

This is the first equation of motion, relating final velocity to initial velocity, acceleration, and time

s = ut + (1/2)at²

This is the second equation of motion, relating displacement to initial velocity, acceleration, and time

v² = u² + 2as

This is the third equation of motion, relating final velocity to initial velocity, acceleration, and displacement

Where:

v = final velocity

u = initial velocity

a = acceleration

t = time

s = displacement.

These equations are used in kinematics, which is the study of motion.

They are applicable when dealing with constant acceleration and motion in a straight line.