Answer:
The frequency of wave is 160Hz.
Explanation:
Given that the formula of speed is V = f×λ where V represents speed, f is frequency and λ is wavelength.
So first thing, you have to make frequency the subject by dividing wavelength on both sides :



Next you have to substitute the value of v and f into the formula :
Let λ = 2.5m,
Let v = 400m/s,


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:Explanation: According to Newton's third law, the force exerted by the bat hitting the ball will be equal in magnitude but opposite in direction of the force the ball exerts on the bat. Generally, your arms are stiff when you hit the ball forward, so you will not feel the bat "recoiling".
Explanation:
Answer: No sure what to do
Explanation: points for points
Answer:
Newton's third law of motion.
Explanation:
We are told the force needed to throw the full soda can was more than that needed to throw the empty can.
Now, the weight of the full soda can will be more than that of the empty can. Therefore, the full can will demand more force than that of the empty can due to Newton's third law of motion which states that to every action, there is an equal and opposite reaction.