Answer: The frequency heard will be f = 275.675Hz
Explanation: When an object emitting sound is moving, it occurs a phenomenon called Doppler shift or Doppler effect. What happens is that the sound gets higher when the moving object comes closer the observer and becomes lower after it passes, This change is due to the quantity of waves that passes through an area in an unit of time.
The formula to calculate the Doppler effect is as follows
f = (
) · f₀
f is the observed frequency;
c is the speed of sound;
Vs is velocity of the source;
f₀ is the emitted frequency of source;
Substituting and calculating,
f = 
· 300
f = 275.675 Hz
Thus, the frequency heard by the police officer is 275.675Hz.
Answer:
coasting down hill on a bicycle
Explanation:
Coasting down the hill on a bicycle is a typical example of how kinetic energy is being transformed to potential energy in a system.
Kinetic energy is the energy due to the motion of a body, it can be derived using the expression below;
K.E = 
m v²
Potential energy is the energy due to the position of a body. It can be derived using;
P.E = mgh
m is the mass
v is the velocity
g is the acceleration due to gravity
h is the height
Now, at the top of the hill, the potential energy is at the maximum. As the bicycle coasts down the potential energy is converted to kinetic energy.
Answer:
360 Nm
Explanation:
Torque: This is the force that tend to cause a body to rotate or twist. The S.I unit of torque is Newton- meter (Nm).
From the question,
The expression of torque is given as
τ = F×d......................... Equation 1
Where, τ = Torque, F = force, d = distance of the bar perpendicular to the force.
Given: F = 40 N, d = 9 m
Substitute into equation 1
τ = 40(9)
τ = 360 Nm.
The reason you only see fossils in sedimentary rock is that these set of rocks are formed in much lower pressure and temperature, compared to the other types of rocks like igneous rocks.
Subjective refers to something that takes place within the mind of the person. It is modified based on individual bias.
Objective refers to defining things or expressing them without any distortion. They are expressed only as perceived.
Finally, mineral is anything composed of matter apart from animals and plants.
