Answer: acceleration due to gravity of planet a would be twice that of planet b. Given that the radius are thesame.
Explanation:
Acceleration due to gravity is as a result of the gravitational force of attraction of a planet to its centre.
g = GM/r^2
Where;
g = acceleration due to gravity
G = gravitational constant
M = mass of planet
r = radius of planet
Given that the two planet have the same radius, if the mass of planet a is twice the mass of planet b the the acceleration due to gravity of planet a would be twice that of planet b, because acceleration due to gravity is directly proportional to the mass of the planet.
Answer:

Explanation:
wavelength, λ = 2.5 m
speed, v = 13.8 m/s
Amplitude, A = 0.14 m
The general equation of the transverse harmonic wave which is travelling right is given by

where, Ф is phase
At t = 0, x = 0 , y = 0.14 m
0.14 = 0.14 Sin Ф
Ф = π/2
So, the equation is


Quantum Theory is commonly related to Quantum Mechanics, or the physics of sub-atomic particles. Quantum Theory defines the theories or educated ideas behind Quantum Mechanics. I believe this is the answer you are looking for.
Answer:
The frequency of sound heard by the boy is 1181 Hz.
Explanation:
Given that,
Frequency of sound from alarm 
Speed = -8.25 m/s
Negative sign show the boy riding away from the car
Speed of sound = 343
We need to calculate the heard frequency
Using formula of frequency

Where,
= frequency of source
= speed of observer
= speed of source
= speed of sound
Put the value into the formula

here, source is at rest


Hence, The frequency of sound heard by the boy is 1181 Hz.