Answer:
Since there are hundreds of nails, instead of puncturing your skin the nails actually support you.
Explanation:
If you step on the point of a nail, your foot exerts a tremendous amount of pressure on the nail's tiny point. As a result, the point can go straight through your foot. But a bed of nails has lots of points that are close together -- there's a lot of surface area for the body to cover. Hundreds of nails support the weight of your body instead of just one. Typically, your body doesn't exert enough pressure on any one nail for it to break the skin. You can even place a second bed on top of you and break a cinderblock on it. The resulting force is distributed over all of the nails, so you shouldn't be injured.
Explanation:
Given that,
Initial speed of the rock, u = 30 m/s
The acceleration due to gravity at the surface of the moon is 1.62 m/s².
We need to find the time when the rock is ascending at a height of 180 m.
The rock is projected from the surface of the moon. The equation of motion in this case is given by :

It is a quadratic equation, after solving whose solution is given by:
t = 7.53 s
or
t = 8 seconds
(e)If it is decending, v = -20 m/s
Now t' is the time of descending. So,

Let h' is the height of the rock at this time. So,

or
h' = 155 m
Answer:
if the frequency of the wave if tripled then period of wave gets tripled
Answer:
<em>A = 6.9 cm</em>
Explanation:
<u>Simple Harmonic Motion</u>
A mass-spring system is a common example of a simple harmonic motion device since it keeps oscillating when the spring is stretched back and forth.
If a mass m is attached to a spring of constant k and they are set to oscillate, the angular frequency of the motion is

The equation for the motion of the object is written as a sinusoid:

Where A is the amplitude.
The instantaneous speed is computed as the derivative of the distance

And the maximum speed is

Solving for the amplitude

Computing w

Calculating A

