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Pressure is defined as force per unit area. In the context of gas molecules colliding with the walls of a container, the force exerted by the gas can be understood as the rate at which momentum is transferred to the walls. As gas molecules collide with the walls, they change momentum, and this change occurs over time. Thus, the pressure can be described as the rate of change of momentum (change in momentum per collision multiplied by the number of collisions per second) divided by the area over which the collisions occur.

A rainbow is formed by the DISPERSION of sunlight by spherical raindrops floating in the air.

Object distance (u) = -25 cm (negative because the object is in front of the mirror) Image distance (v) = +5 cm (positive because the image is behind the convex mirror) Using \(\frac{1}{f}\) = \(\frac{1}{u}\) + \(\frac{1}{v}\) \(\frac{1}{f}\) = \(\frac{1}{-25}\) + \(\frac{1}{5}\) f = \(\frac{25}{4}\) = 6.250cm.

The Power is given by: P = \(\frac{1}{f}\) f = 20cm → 0.2m P = \(\frac{1}{0.2}\) = 5 dioptres

A monochromatic light is one that has a single wavelength or color. This means that it consists of light waves that all have the same frequency, resulting in a uniform appearance without any variation.

The diaphragm in a camera is similar to the D. Iris of the eyes. The diaphragm controls the amount of light entering the camera, just as the iris controls the amount of light entering the eye by adjusting the pupil's size.

The horizontal component F\(_x\) can be calculated using the formula: F\(_x\) = F⋅ cos (\(\theta\)) F = 150N and \(\theta\) = 60º F\(_x\) = 150 x 0.5 = 75N (cos 60º = 0.5)

D. Not recovery devices. In contrast, the other options—A. The body tube, B. The nose cone, and C. The fin—are all essential components of a model rocket. Recovery devices (like parachutes or streamers) are also important for ensuring a safe landing, but "not recovery devices" are not a specific part of the rocket itself.

Streaming refers to the streamlined shape of an object, which helps minimize air resistance (drag) as it moves through the air. This is often applied in aerodynamics to improve the efficiency of vehicles and objects moving through air.

W\(_{moon}\) = mass x g = mass x \(\frac{10}{6}\) = \(\frac{10m}{6}\)N W\(_{earth}\) = mass x g = mass x 10 = 10m mass = constant g on earth = 10m/s\(^2\) and g on moon = \(\frac{1}{6}\) x that on earth Therefore, The weight of a bowling ball on the moon would be \(\frac{1}{6}\), the weight on earth.

Angular velocity(\(\omega\)) = 2\(\pi\) x rev per sec Rev. per sec = \(\frac{800}{60}\) \(\approxeq\) 13.33 rev/s Angular velocity(\(\omega\)) = 2\(\pi\) x 13.33 \(\approxeq\) 26.7\(\pi\)rad/s

The tangential force acting on an object that prevents it from sliding freely on the adjacent surface is called friction. Friction plays a crucial role in preventing or resisting motion between surfaces in contact.

Effective horizontal force = 15N T = tension on the rope F\(_x\) = T sin\(\theta\) 15 = T x sin 30º T = \(\frac{15}{0.5}\) = 15 x 2 = 30N.

Work is done when a force causes an object to move in the direction of that force. OPTION C. A boy climbs onto a table. Work done (force is applied to lift himself). when a boy climbs onto a table, he exerts a force to lift his body against gravity. As he moves upward, he is doing work because there is a displacement in the direction of the applied force. Thus, work is done in this case.

The energy in a moving car is an example of kinetic energy which is the energy possessed by a body in motion.