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.
Malleable
Malleability
is a property of matter, that’s specializes in metals, in which these metals
can be bended, twisted or formed into a thinner sheets, and not being able to
shatter to pieces instead it can be formed into a new shape. Unlike the other
three, take for instance hardness. If a hard object such as wood for example
when used with an axe it breaks and it is lead to smithereens. Flammable like
is when applied to fire can dramatically explode when hit it obviously breaks.
Answer:
Acceleration and velocity Newton's second law says that when a constant force acts on a massive body, it causes it to accelerate, i.e., to change its velocity, at a constant rate. In the simplest case, a force applied to an object at rest causes it to accelerate in the direction of the force.
Let's calculate the average acceleration. It is the rate of changing speeds. Hence, we need to calculate the difference of speeds. 10-6=4 m/s. The rate is now
.
In general, the formula for the mean acceleration between two times 1 and 2 is given by:
where v1 and v2 are the speeds at the respective points and T is the time interval between them.
Answer:
The pressure on the floor is 12 Pascal(Pa).
Explanation:
Given,
Force (F) = 240N
Area (A) = 20 cm^2
Pressure (P) = ?
we know that,
P = F/A
= 240/ 20
= 12 Pa
