Which one of the following devices converts radioactive emissions to light for detection?

The blood plays an important role in removing heat from th ebody by bringing the heat directly to the surface where it can radia

BabaBlast [244]

Answer: Thermal comductivity (K) is 3.964x 10 ^-3 W/m.k

Explanation:

Thermal comductivity K = QL/A∆T

Q= Amount of heat transferred through the material in watts = 75W

L= Distance between two isothermal planes = 0.740mm

A= Area of the surface in square metres = 2m^2

∆T= Temperature change = (37-30) °C.

Solving this : K =( 75 x 0.740 x 10^-3)/ 2 x (37-30)

K = 3.964x 10 ^-3 W/m.k

7 0

2 years ago

A farm hand does 972 J of work pulling an empty hay wagon along level ground with a force of 310 N [23° below the horizontal]. T

irina1246 [14]

Answer:

Option d)

Solution:

As per the question:

Work done by farm hand, $W_{FH} = 972J$

Force exerted, F' = 310 N

Angle, $\theta = 23^{\circ}$

Now,

The component of force acting horizontally is F'cos $\theta$

Also, we know that the work done is the dot or scalar product of force and the displacement in the direction of the force acting on an object.

Thus

$W_{FH} = \vec{F'}.\vec{d}$

$972 = 310\times dcos23^{\circ}$

d = 3.406 m = 3.4 m

3 0

2 years ago

Although blood cells are contained within a special liquid called plasma, the cells themselves are___________.

valentina_108 [34]

Answer:

Solid

Explanation:

The plasma is the liquid part of blood, it is 90% and accounts for 55% of blood volume. It is what red blood cells, white blood cells, and platelets move around in. These cells remain solid within the plasma. I hoped this helped!

8 0

2 years ago

The wavelength of green light is 550 nm.

SIZIF [17.4K]

Answer:

(a) momentum of photon is 1.205 x 10⁻²⁷ kgm/s

velocity of electron is 1323.88 m/s

momentum of the electron is 1.205 x 10⁻²⁷ kgm/s

(b) momentum of photon is 1.506 x 10⁻²⁷ kgm/s

velocity of electron is 1654.85 m/s

momentum of the electron is 1.506 x 10⁻²⁷ kgm/s

(c) The momentum of the photon is equal to the momentum of the electron

Explanation:

(a)

wavelength of green light, λ = 550 nm

momentum of photon is given by;

$p = \frac{h}{\lambda}\\\\ p = \frac{6.626 *10^{-34}}{550*10^{-9}}\\\\p = 1.205 *10^{-27} \ kg.m/s$

velocity of electron is given by;

$P = \frac{h}{\lambda} \\\\mv = \frac{h}{\lambda}\\\\v = \frac{h}{m \lambda}\\\\v = \frac{6.626 *10^{-34}}{(9.1*10^{-31} )(550*10^{-9})}\\\\v = 1323.88 \ m/s$