Answer:
P.E = 13230 J
Explanation:
Given,
The mass of the rock, m = 45 Kg
The rock is sitting at a height from the ground, h = 30 m
The acceleration due to gravity, g = 9.8 m/s²
The potential energy of the body is given by the formula,
P.E = mgh joules
Substituting the given values in the above equation
P.E = 45 x 9.8 x 30
= 13230 J
Hence, the potential energy of the rock is P.E = 13230 J
Answer:
People with presbyopia require a convex lens for reading glasses; specialized preparations of convex lenses usually require the services of an optometrist
Answer:
390 J
Explanation:
m = 3 kg
u = 16 i + 2 j
(a) Magnitude of velocity = 
= 16.1245 m/s
KEi = 1/2 m v^2 = 0.5 x 3 x 16.1245 = 390 J
(b) v = 18 i + 14 j
Magnitude of velocity = 
= 22.804 m/s
KEf = 1/2 m v^2 = 0.5 x 3 x 22.804 = 780 J
According to the work energy theorem
Work done = change in KE = KEf - KEi = 780 - 390 = 390 J
Answer: The correct answer is (a).
Explanation:
The potential energy is due to the position of the object.
The kinetic energy is due to the motion of the object.
In the case of a basketball sitting on a shelf, the basketball posses the potential energy due to some height.
In the case of a dog running across a field, a dog has kinetic energy due to its motion.
In a case of a bowling ball rolling down a lane, there is kinetic energy due to the motion of the bowling ball.
In the case of a teenager riding their bike, there is kinetic energy due to the motion of the bike.
Therefore, the correct answer is (a).
Answer:
What will be the increase in frequency if these waves are reflected = 2979.63Hz
Explanation:
The detailed steps and appropriate formula is as shown in the attached file.
