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) 
The answer would be threshold voltage. It is the minimum value of voltage needed to produce an action potential. It is also known as gate voltage. It is the minimum value that would make turn a transistor on. Hope this answers the question.

Explanation:
Given:


The cross product
is given by



Answer:
10.8 s
Explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 0 m/s
Acceleration (a) = 5 m/s/s
Distance travelled (s) = 291 m
Time (t) taken =?
We can calculate the time taken for the car to cover the distance as follow:
s = ut + ½at²
291 = 0 × t + ½ × 5 × t²
291 = 0 + 2.5 × t²
291 = 2.5 × t²
Divide both side by 2.5
t² = 291 / 2.5
t² = 116.4
Take the square root of both side
t = √116.4
t = 10.8 s
Thus, it will take the car 10.8 s to cover the distance.
You've already told us the speed in ft/s . It's right there in the question. You said that light travels about 982,080,000 ft/s.
We don't know how accurate that number is, but for purposes of THIS question, that's the number we're going with.
In scientific notation, it's written . . . <em>9.8208 x 10⁸ ft/s .</em>
We don't know where you were going with the number of seconds in a year. But to answer the question that you eventually asked, it turned out that we don't even need it.