Physics 2015 Jamb Examination

In an inelastic collision, the total linear momentum of the system is always conserved, provided no external forces act on it. However, kinetic energy is not conserved; a portion of the initial kinetic energy is converted into other forms of energy such as heat, sound, or internal potential energy used to deform the colliding objects. Therefore, the total kinetic energy of the system decreases after the collision. This makes statements II and IV correct.

The average normal body temperature is generally accepted as 37°C (98.6°F). However, a healthy person's body temperature can fluctuate throughout the day, typically falling within the range of 36.1°C to 37.2°C. A clinical thermometer is specifically designed to measure this narrow range, usually scaled from 35°C to 42°C. Among the given options, the range 35°C to 37°C most closely aligns with the standard physiological norms for a healthy human body.

Inertia is the inherent property of an object that resists any change in its state of rest or uniform motion in a straight line. This concept is the foundation of Newton's First Law of Motion, often called the Law of Inertia. The amount of inertia an object possesses is directly proportional to its mass; a more massive object requires more force to change its state of motion than a less massive one.

An elastic collision is defined as an encounter between two bodies in which the total kinetic energy and the total linear momentum are both maintained. No energy is lost to the surroundings as heat or sound, and the objects do not undergo permanent deformation. In contrast, inelastic collisions and explosions conserve momentum but involve a change (usually a loss) in total kinetic energy.

The period (\(T\)) of an alternating current is the time taken to complete one full cycle. It is the reciprocal of the frequency (\(f\)).
Given:
Frequency \(f = 100 \text{ Hz}\)
The relationship is:\[ T = \frac{1}{f} \]\[ T = \frac{1}{100} = 0.01 \text{ sec} \]Thus, the time required for one cycle of a 100Hz signal is 0.01 seconds.