No...........................................................................Work for them urself
Answer: The frequency = 1714.3Hz
Explanation: The solution can be achieved by using doppler effect formula.
Since the source is moving toward the observer, the velocity of the observer will be positive.
Please find the attached file for the solution
Answer:

Explanation:
The amount of work done by Devin when moving the lawn is given by:

where
F is the average force applied
d is the displacement of the lawn
is the angle between the direction of the force and the displacement
Assuming that Devin moves the lawn by applying a force parallel to the displacement, we have:
F = 75 N
d = 1.5 km = 1500 m

Therefore, the work done is

Answer:
9.81 m/s^2
Explanation:
Acceleration is constant 9.81 m/s^2 ( of course....ignoring air friction)