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Ilia_Sergeevich [38]

3 years ago

14

Is an object speeding up or slowing down of the V final is greater than the V initial?

1 answer:

sertanlavr [38]3 years ago

7 0

Answer:

V is greater

Explanation:

because v intial at that time V final is the that speed which it is going at that time

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When Casey looks at a CD or DVD she notices that there is a rainbow pattern that is created by the light. She became curious and

ipn [44]

Answer:

Explanation:

diffraction

6 0

3 years ago

Read 2 more answers

Depending on circumstances, there are times when divers may wish to be positively, negatively or neutrally buoyant. True. False.

ser-zykov [4K]

Answer:

True

Explanation:

Buoyancy is the most important factors for divers. All they do underwater is to observe the life down there but they also have some other work. However, divers may want to be negatively buoyant when they want to go on deep exploration. When they reach a destination, they may want to observe and neutral buoyancy then will be useful. When they want to go back on surface, they’ll utilize positive buoyancy.

7 0

3 years ago

A counterflow double-pipe heat exchanger is used to heat water from 20°C to 80°C at a rate of 1.2 kg/s. The heating is to be com

bixtya [17]

Answer:L=109.16 m

Explanation:

Given

initial temperature $=20^{\circ}C$

Final Temperature $=80^{\circ}C$

mass flow rate of cold fluid $\dot{m_c}=1.2 kg/s$

Initial Geothermal water temperature $T_h_i=160^{\circ}C$

Let final Temperature be T

mass flow rate of geothermal water $\dot{m_h}=2 kg/s$

diameter of inner wall $d_i=1.5 cm$

$U_{overall}=640 W/m^2K$

specific heat of water $c=4.18 kJ/kg-K$

balancing energy

Heat lost by hot fluid=heat gained by cold Fluid

$\dot{m_c}c(T_h_i-T_h_e)= \dot{m_h}c(80-20)$

$2\times (160-T)=1.2\times (80-20)$

$160-T=36$

$T=124^{\circ}C$

As heat exchanger is counter flow therefore

$\Delta T_1=160-80=80^{\circ}C$

$\Delta T_2=124-20=104^{\circ}C$

$LMTD=\frac{\Delta T_1-\Delta T_2}{\ln (\frac{\Delta T_1}{\Delta T_2})}$

$LMTD=\frac{80-104}{\ln \frac{80}{104}}$

$LMTD=91.49^{\circ}C$

heat lost or gain by Fluid is equal to heat transfer in the heat exchanger

$\dot{m_c}c(80-20)=U\cdot A\cdot$ (LMTD)

$A=\frac{1.2\times 4.184\times 1000\times 60}{640\times 91.49}=5.144 m^2$

$A=\pi DL=5.144$

$L=\frac{5.144}{\pi \times 0.015}$

$L=109.16 m$

6 0

3 years ago

A children's roller coaster is released from the top of a track. If its maximum speed at ground level is 3 m/s, find the height

san4es73 [151]

Answer:

h = 0.46 m

Explanation:

According to the law of conservation of energy:

Potential Energy Lost by Roller Coaster = Kinetic Energy Gained by Roller Coaster

$mgh = \frac{1}{2}mv^2\\\\2gh = v^2\\\\h = \frac{v^2}{2g}$

where,

h = height = ?

v = speed at bottom = 3 m/s

g = acceleration due to gravity = 9.81 m/s²

Therefore,

$h = \frac{(3\ m/s)^2}{(2)(9.81\ m/s^2)}$

<u>h = 0.46 m</u>

4 0

3 years ago

A space shuttle is flying north at 6,510 m/s. It

Maksim231197 [3]

Answer:

7808 m/s

Explanation:

Find NE velocity after 60 s of acceleration in that direction:

= a t = 28.4 m/s^2 * 60 s = 1704 m/s

Vertical component = 1704 sin 45 = 1204.9 m/s

Horiz component = 1704 cos 45 = 1204.9 m/s

Add the two vertical components

6510 + 1204.9 = 7714.9 m/s = vertical velocity

Pythagorean theorem to find resultant of vertical and horiz v's

Vf ^2 = 1204.9^2 + 7714.9^2 0

Vf = 7808. m/s

7 0

2 years ago