Answer:
c. 2 m/s
Explanation:
The speed of a wave is given by:

where
v is the speed of the wave
f is the frequency
is the wavelength
For the wave in this problem, we have
f = 4 Hz is the frequency
is the wavelength
So, the speed of the wave is

It is a surface force
<span />
Answer:
3.25 seconds
Explanation:
It is given that,
A person throws a baseball from height of 7 feet with an initial vertical velocity of 50 feet per second. The equation for his motion is as follows :

Where
s is the height in feet
For the given condition, the equation becomes:

When it hits the ground, h = 0
i.e.

It is a quadratic equation, we find the value of t,
t = 3.25 seconds and t = -0.134 s
Neglecting negative value
Hence, for 3.25 seconds the baseball is in the air before it hits the ground.
Answer:
distance= velocity ×time
distance= 62×10
distance=620m
hope it helps you mate please mark me as brainliast