Explanation

In free fall (neglecting air resistance), all bodies have the same acceleration due to gravity (g = 9.8 m/s²).

Their kinetic energy and momentum differ because they depend on mass.

Explanation

Force between charges depends on the product q1q2.

If one charge becomes zero, the product becomes zero → no attraction or repulsion.

Explanation

Total energy in SHM E∝A² (energy depends on the square of amplitude).

To double the energy, amplitude must increase by √2 times.

Explanation

Wave speed on a string v = √T/μ, where μ is mass per unit length.

Thinner strings have smaller 𝜇, so waves travel faster on them.

Explanation

The Moon takes the same time to rotate once on its axis as it does to revolve once around the Earth.

That’s why we always see the same side of the Moon from Earth.

Explanation

A calculator display uses a 7-segment LED to form digits 0–9.

Each segment lights up in different combinations to show different numbers.

Explanation

The first excitation energy means energy needed to move an electron from n = 2 to n = 2.

Energy difference = 13.6 - 3.4 = 10.2 eV.

Explanation

At the extreme point of motion, the glider’s velocity becomes zero.

The acceleration is negative, pulling it back toward the mean position.

Explanation

Current is voltage divided by resistance.

With 120 V and 1000 Ω, current is very small, only 0.12 A.

Explanation

In a series RLC circuit at resonance, the inductive voltage 𝑉𝐿 and capacitive voltage 𝑉𝐶 are equal but opposite.

So they cancel each other when we calculate the total applied voltage.

V applied = √C²R + (VL - VC)²

Substitute the given values:

V applied = √10² + (30-30)² = √100+0 = 10V