Answer:
P = 1471500 [Pa]
Explanation:
We must remember that pressure is defined as the relationship between Force over the area.

where:
P = pressure [Pa] (units of pascals)
F = force [N] (units of Newtons)
A = area of contact = 4 [cm²]
But first we must convert from cm² to m²
![A = 4[cm^{2}]*\frac{1^{2} m^{2} }{100^{2} cm^{2} }](https://tex.z-dn.net/?f=A%20%3D%204%5Bcm%5E%7B2%7D%5D%2A%5Cfrac%7B1%5E%7B2%7D%20m%5E%7B2%7D%20%7D%7B100%5E%7B2%7D%20cm%5E%7B2%7D%20%7D)
A = 0.0004 [m²]
Also, the weight should be calculated as follows:

where:
m = mass = 60 [kg]
g = gravity acceleration = 9.81 [m/s²]
Now replacing:
![w = 60*9.81\\w = 588.6[N]](https://tex.z-dn.net/?f=w%20%3D%2060%2A9.81%5C%5Cw%20%3D%20588.6%5BN%5D)
And the pressure:
![P=588.6/0.0004\\P=1471500 [Pa]](https://tex.z-dn.net/?f=P%3D588.6%2F0.0004%5C%5CP%3D1471500%20%5BPa%5D)
Because 1 [Pa] = 1 [N/m²]
We have that F=ma from the 2nd Newton law where F is the force, m is the mass and a is the acceleration. Suppose we have that F' is the new force and m' is the new mass. Then, we have that a'=F'/m' still, by rearranging Newton's law. We are given that F'=2F and m'=m/2. Hence,

But now, we have from F=ma, that a=F/m and we are given that a=1m/s^2.
We can substitute thus, a'=4a=4*1m/s^2=4m/s^2.
Answer:
- Waves with higher amplitude transfer HIGHER energy.
- Waves with higher frequency transfer HIGHER energy.
Answer:
5.714 hours / day
Explanation:
<u>Calculate the hours used in that week </u>
120000 / 3000 = 120 / 3 = 40 hours a week
<u>Calculate the amount it is used in one day</u>
40 / 7 = 5.71428571 hours or 5.714 hours/day
Let the key is free falling, therefore from equation of motion
.
Take initial velocity, u=0, so
.

As velocity moves with constant velocity of 3.5 m/s, therefore we can use formula

From above substituting t,
.
Now substituting all the given values and g = 9.8 m/s^2, we get
.
Thus, the distance the boat was from the point of impact when the key was released is 10.60 m.