The correct answer is:
<span>C) The actual frequency of the siren does not change despite appearances.
In fact, Bob will observe an increase in the apparent frequency as the emergency vehicle approaches him, while Jill will observe a decrease in the apparent frequency as the emergency vehicle moves away from him, because of the Doppler effect (the relative velocity between the observer and the source of the sound is changing), but this effect involves the apparent frequency, while the real frequency of the siren will remain the same.</span>
I believe it is, All of the above.
1. 0.2 g/mL
The relationship between mass, density and volume of an object is
where
d is the density
m is the mass
V is the volume
For the object in this problem, we have
m = 10 g
V = 50 mL
Substituting into the equation,
2. 10 mL
In this exercise we know:
- The density of the object: d = 2 g/mL
- The mass of the object: m = 20 g
Therefore, we can re-arrange the previous equation to find the volume:
And substituting values into the equation, we find
Frictional forces act in the direction opposite to the MOTION. That direction could be the same OR opposite to applied force.
-- If you push a loaded heavy wagon from behind, trying to get it going faster, friction is acting against you, opposite to your force.
-- If you push a loaded rolling heavy wagon from in front, trying to make it slow down, friction is acting with you, in the same direction as your force.
-- Opposite to the motion both times.
Answer: It does not include alpha rays
Explanation: It does not include alpha rays
