Answer:
Advantages: In small quantities they help your body produce vitamin D.
Disadvantages: They can cause sunburn or even skin cancer if used in large quantities.
Explanation:
A and c...............................
Answer:
Because the disturbances are in opposite directions for this superposition, the resulting amplitude is zero for pure destructive interference
Explanation:
To develop this problem it is necessary to apply the concepts related to the Dopler effect.
The equation is defined by
Where
= Approaching velocities
= Receding velocities
c = Speed of sound
v = Emitter speed
And
Therefore using the values given we can find the velocity through,
Assuming the ratio above, we can use any f_h and f_i with the ratio 2.4 to 1
Therefore the cars goes to 145.3m/s
Answer:
The average velocity has magnitude = 10 km/h , direction: east
Explanation:
In order to find the average velocity of the car we need to know the final and initial positions, and the time that took to get from one to the other.
Notice that since its movement was 60 km straight east and then from there 40 km straight west, the car is positioned at 20 km to the east of its initial departure point. therefore the vector change in position is a vector 20 km in magnitude, and direction towards the east.
Since it took the car a total of 1.33 hours plus 0.67 hours to reach its final position, the total time elapsed is: 1.33 + 0.67 hours = 2 hours.
Then,the velocity vector has magnitude; 20 km / 2 hours = 10 km/hour
As we mentioned above. the direction of the velocity vector is east.
