True, because people should reach their full potential within themselves and human psychologist should help those that need help to reach it.
The answer is c you got to look for answers that make sense
Answer:
A. Kinetic energies are equal.
Explanation:
The kinetic energy of the bodies will be equal since the mass and speed are the same.
Kinetic energy is the energy due to the motion of a body.
Mathematically;
K.E =
m v²
m is the mass
v is the speed
The kinetic energy is a scalar quantity with no regard for direction.
Answer:
(a) 89 m/s
(b) 11000 N
Explanation:
Note that answers are given to 2 significant figures which is what we have in the values in the question.
(a) Speed is given by the ratio of distance to time. In the question, the time given was the time it took the pulse to travel the length of the cable twice. Thus, the distance travelled is twice the length of the cable.
![v=\dfrac{2\times 620 \text{ m}}{14\text{ s}} = \dfrac{1240\text{ m}}{14\text{ s}}=88.571428\ldots \text{ m/s}= 89\text{ m/s}](https://tex.z-dn.net/?f=v%3D%5Cdfrac%7B2%5Ctimes%20620%20%5Ctext%7B%20m%7D%7D%7B14%5Ctext%7B%20s%7D%7D%20%3D%20%5Cdfrac%7B1240%5Ctext%7B%20m%7D%7D%7B14%5Ctext%7B%20s%7D%7D%3D88.571428%5Cldots%20%5Ctext%7B%20m%2Fs%7D%3D%2089%5Ctext%7B%20m%2Fs%7D)
(b) The tension,
, is given by
![v =\sqrt{\dfrac{T}{\mu}}](https://tex.z-dn.net/?f=v%20%3D%5Csqrt%7B%5Cdfrac%7BT%7D%7B%5Cmu%7D%7D)
where
is the speed,
is the tension and
is the mass per unit length.
Hence,
![T = \mu\cdot v^{2}](https://tex.z-dn.net/?f=T%20%3D%20%5Cmu%5Ccdot%20v%5E%7B2%7D)
To determine
, we need to know the mass of the cable. We use the density formula:
![\rho = \dfrac{m}{V}](https://tex.z-dn.net/?f=%5Crho%20%3D%20%5Cdfrac%7Bm%7D%7BV%7D)
where
is the mass and
is the volume.
![m=\rho\cdot V](https://tex.z-dn.net/?f=m%3D%5Crho%5Ccdot%20V)
If the length is denoted by
, then
![\mu = \dfrac{m}{l} = \dfrac{\rho\cdot V}{l}](https://tex.z-dn.net/?f=%5Cmu%20%3D%20%5Cdfrac%7Bm%7D%7Bl%7D%20%3D%20%5Cdfrac%7B%5Crho%5Ccdot%20V%7D%7Bl%7D)
![T = \dfrac{\rho\cdot V}{l} v^{2}](https://tex.z-dn.net/?f=T%20%3D%20%5Cdfrac%7B%5Crho%5Ccdot%20V%7D%7Bl%7D%20v%5E%7B2%7D)
The density of steel = 8050 kg/m3
The cable is approximately a cylinder with diameter 1.5 cm and length or height of 620 m. Its volume is
![V = \pi \dfrac{d^{2}}{4} l](https://tex.z-dn.net/?f=V%20%3D%20%5Cpi%20%5Cdfrac%7Bd%5E%7B2%7D%7D%7B4%7D%20l)
![T = \dfrac{\rho\cdot\pi d^2 l}{4l}v^2 = \dfrac{\rho\cdot\pi d^2}{4}v^2](https://tex.z-dn.net/?f=T%20%3D%20%5Cdfrac%7B%5Crho%5Ccdot%5Cpi%20d%5E2%20l%7D%7B4l%7Dv%5E2%20%3D%20%5Cdfrac%7B%5Crho%5Ccdot%5Cpi%20d%5E2%7D%7B4%7Dv%5E2)
![T = \dfrac{8050\times\pi\times0.015^2}{4} \times 88.57^2](https://tex.z-dn.net/?f=T%20%3D%20%5Cdfrac%7B8050%5Ctimes%5Cpi%5Ctimes0.015%5E2%7D%7B4%7D%20%5Ctimes%2088.57%5E2)
![T = 11159.4186\ldots \text{ N} = 11000 \text{ N}](https://tex.z-dn.net/?f=T%20%3D%2011159.4186%5Cldots%20%5Ctext%7B%20N%7D%20%3D%2011000%20%5Ctext%7B%20N%7D)