When the sound wave returns to the machine, you can measure
how long it took to return.
(You may notice that it's working just like RADAR, which does the
same thing with radio waves instead of sound waves.)
Even if you know how long the sound took to get to the bottom and
return to the top, you can't DO anything with this information if you
don't know the SPEED of the sound through the water. Not only
the inventory of this machine, but anyone who uses it, has to know
the speed of the sound through water in order to use the round-trip
time to calculate the depth.
Explanation:
It is given that,
The Displacement x of particle moving in one dimension under the action of constant force is related to the time by equation as:

Where,
x is in meters and t is in sec
We know that,
Velocity,

(a) i. t = 2 s

At t = 4 s

(b) Acceleration,

Pu t = 3 s in the above equation
So,

Hence, this is the required solution.
<span>Protein is the type of food which is retered to as the building block of human body. Other functions of protein includes: it is a component of every part of the body especsially the hairs and nails. The body uses it to build and repair tissues, Itis used by the body to produce enzymes, hormones and other body chemicals. It is also the building block for bones, muscels, cartilages, skin and blood.</span>
Explanation:
w = f x d
45 x 1.4 = 630j
to get newton's do 45 x gravitation field strength