Answer:
decibels (dB)
Explanation:
The sound intensity level is a quantity derived from the sound intensity.
The intensity of a wave is defined as the power of the source of the wave divided by the area through which the power of the wave is spread, mathematically:
where
P is the power of the source
is the surface area over which the wave spreads (assuming that the wave propagates in all directions, it corresponds to the surface area of a sphere of radius 
, where r is the distance between the source of the wave and the observer)
For sound waves, the intensity is often expressed using another unit, called decibel (dB), defined as follows:
where
is the sound intensity level in decibels
I is the intensity of the sound wave
is the threshold intensity of a sound that a person can normally hear.
Answer: C solar energy
Solar energy has the greatest impact on primary productivity.
Explanation:
Primary productivity is the amount of organic compounds synthesized from carbon dioxide. Primary production occurs by the process of photosynthesis. Since the process of photosynthesis uses sunlight as the energy source solar energy has the greatest impact on primary productivity.
The synthesis can occur in atmosphere as well as aquatic environment. The organisms that perform the function of primary production are called producers .In terrestrial regions plants are the producers and in aquatic systems algae are the primary producers.
Answer:
Explanation:
The period of oscillation will remain unchanged because the period of oscillation of a pendulum does not depend upon the mass of the bob . Here monkey along with bunch of banana represents bob .
When the monkey and banana were at height h /2 , they have potential energy as well as kinetic energy . banana is separated from the system . It carried its total energy along with it . But the energy of monkey remained intact with it . So it will keep on moving as usual . So it will attain the same maximum height as before .
Hence the amplitude of oscillation too will remain unchanged .
A.Momentum Equation
m = mass = 75 kg
v = velocity = 18 m/s
P = momentum
Using the momentum equation , momentum is given as
P = mv
P = 75 x 18
P = 1350 kgm/s
Answer:
Normal, Gravity, Friction, and Air Resistance.
Explanation:
When a moving car skid to stop and its wheels are locked across, then the following forces will be applied on the car:
<u>Normal force:</u> It will act counter to gravity that pushes an object against a surface and acts perpendicular to the contact surface.
<u>Gravity:</u> Gravity force acts in each and every object having mass and it can not be avoidable. So, the gravity force will also apply to the car and attract it to the earth's surface.
<u>Friction: </u>Friction is a force that acts opposite to the motion and stops or slows motion. Friction will be applied to the car that will oppose the motion of the car and stop it.
<u>Air resistance:</u> air resistance is defined as the forces exerted by air that acts opposite to the relative motion of an object. Air resistance will also be applied to the car when it will skid to stop as we are always surrounded by the air.
Hence, the correct answers are "Normal, Gravity, Friction, and Air Resistance."
