Answer:
a) 30.84m/s
b) 348.32Hz
c) 32.34m/s
d) 289.69Hz
Explanation:
a) If 1 mile=1609,34m, and 1 hour=3600 seconds, then 69mph=69*1609.34m/3600s=30.84m/s
b) Based on Doppler effect:
/*I will take as positive direction the vector
*/


c) 
d) 
Answer:
thymine
Explanation:
The nitrogen base found only in DNA is known as thymine which is also called 5-methyl uracil as thymine is a derivative of uracil.
Objects that conduct electricity poorly are called non-metals.
Answer:
it can occur in all waves because all wave have a frequency
Answer:
Second option 6.3 N at 162° counterclockwise from
F1->
Explanation:
Observe the attached image. We must calculate the sum of all the forces in the direction x and in the direction y and equal the sum of the forces to 0.
For the address x we have:

For the address and we have:

The forces
and
are known

We have 2 unknowns (
and b) and we have 2 equations.
Now we clear
from the second equation and introduce it into the first equation.

Then

Then we find the value of 

Finally the answer is 6.3 N at 162° counterclockwise from
F1->