Tag: science & technology

Objects that sink still experience buoyant force equal to the weight of the displaced water (Archimedes' principle). They sink because their weight is greater than the buoyant force, not because buoyancy is absent.

When the bus suddenly accelerates forward, our bodies tend to maintain their state of rest (Newton's first law). This inertia causes us to lean backward relative to the now-moving bus.

Under standard atmospheric pressure, the melting point of ice and freezing point of water both occur at 0°C (32°F). These are phase transition temperatures at which ice and liquid water coexist in equilibrium.

Voltage is electric potential energy per unit charge (joules per coulomb), not a force. The electric field exerts force on electrons; voltage is the potential difference that drives current flow.

Decibels use a logarithmic scale, so adding sound sources doesn't add decibel values linearly. Two identical 90 dB sources combine to approximately 93 dB, not 180 dB.

With 12V across human body resistance (approximately 12,000Ω hand-to-hand), the current is only about 1mA (I=V/R). This is far below the fatal 100mA threshold. The battery's 100A rating is maximum capacity, not actual current delivered.

Even without gravity, accelerating a more massive object requires more force (F=ma). To throw both at the same speed, you must exert greater force on the 4kg shot put than the 0.5kg baseball.

The total upward force from the floor always equals your weight (Newton's third law). Standing on tiptoes reduces contact area, increasing pressure, but the total force remains the same as when flat-footed.