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The power of a lens is defined as the reciprocal of its focal length in metres: P = \(\frac{100}{f}\) → 2.5 = \(\frac{100}{f}\) where P is the power in diopters and f is the focal length in metres. 2.5 * f = 100 f = \(\frac{100}{2.5}\) f = 40 Where f = \(\frac{r}{2}\) radius of the curvature[r] = f * 2 → 40 * 2 r = 80cm

Refraction occurs when light travels from one medium to another which changes the speed at which the light travels. This causes light to bend upon incidence with the interface of a new material. Angle of refraction is smaller than angle of incidence when light ray travels from rarer medium to denser medium. I.e light can either refract towards the normal(when slowing down while crossing the boundary) or away from the normal (when speeding up while crossing the boundary). When light undergoes refraction, its frequency remains the same.

A mechanical wave is a wave that is an oscillation of matter. A sound wave is a mechanical wave that propagates along or through a medium by particle-to-particle interaction. Sound waves, water waves and seismic waves are some examples of mechanical waves mechanical wave.

The relation between period and frequency is that one is the inverse of the other. By definition: Frequency = 1/period. or period = 1/frequency → 1/ 10,000 period = 0.0001 or 1.0 x 10\(^{-4}\) s

In physics, a transverse wave is a wave whose oscillations are perpendicular to the direction of the wave's advance. This is in contrast to a longitudinal wave which travels in the direction of its oscillations. Water waves are an example of transverse wave.

All electromagnetic waves are: transverse waves; can travel through a vacuum ; travel at exactly the same speed in a vacuum, the speed of light, 300,000,000 m/s. transfer energy from one place to another; can be reflected; can be refracted . The oscillations of and are perpendicular to each other and are in the same phase.

beat, in physics, the pulsation caused by the combination of two waves of slightly different frequencies.

speed of the sound wave = \(\frac{distance * 2}{time}\) = \(\frac{408 * 2}{2.4}\) : speed of the sound wave = 340 ms\(^{-1}\)

For a converging lens to act as a simple microscope, the object must be placed at a distance less than one focal length.

Alkaline gases are any gaseous compounds that form an alkali (or basic) solution with a pH greater than 7 when dissolved in water. Ammonia is the most common alkaline gas

Partial pressure is found by Dalton's Law: Px = PTotal ( nx / nTotal ) where Px = partial pressure of gas x PTotal = total pressure of all gases nx = number of moles of gas x nTotal = number of moles of all gases Step 1 Find PTotal Standard pressure is 1 atm. Step 2 Add up the number of moles of the component gases to find nTotal nTotal = noxygen + nnitrogen nTotal = 100 + 900 nTotal =1000cm3 Step 3 Now you have all the information needed to plug the values into the equation and solve for Poxygen P-oxygen = PTotal ( n-oxygen / nTotal ) oxygen = 1 atm ( 100 / 1000 ) oxygen= 0.1atm

It is a graph that represents the force that acts on a body in a certain amount of time. Force on the object is represented by the y-axis and time taken by the object is represented by the y axis. The area under the curve indicates the impulse, the change in momentum that the object undergoes.

The kinetic-molecular theory of gases assumes that ideal gas molecules: (1) are constantly moving; (2) have negligible volume; (3) have negligible intermolecular forces; (4) undergo perfectly elastic collisions; and (5) have an average kinetic energy proportional to the ideal gas's absolute temperature.

Archimede's Principle states that a body immersed in a fluid experiences an upthrust equal to the weight of the fluid displaced, and this is fundamental to the equilibrium of a body floating in still water.

The period of a simple pendulum is doubled, when its length is made four times.