Answer:
The answer is going to be C.
Explanation:
Trust me. Im an expert in physics
Answer:
C.) Gravity
Explanation:
The projectile is an object upon which the only force is gravity. Gravity acts to influence the vertical motion of the projectile.
Answer:
0.79 s
Explanation:
We have to calculate the employee acceleration, in order to know the minimum time. According to Newton's second law:

The frictional force is maximum since the employee has to apply a maximum force to spend the minimum time. In y axis the employee's acceleration is zero, so the net force is zero. Recall that 
Now, we find the acceleration:

Finally, using an uniformly accelerated motion formula, we can calculate the minimum time. The employee starts at rest, thus his initial speed is zero:

Answer:
30 m
Explanation:
The wavelength of a wave is found by the velocity divided by the frequency. Therefore, the wavelength is (300 m/s)/(10 Hz) = 30 m
I hope this helps! :)