For which optical devices does d sometimes have a positive value

A tissue sample at 275 K is submerged in 2 kg of liquid nitrogen at 70 K for cryopreservation. The final temperature of the nitr

kirill115 [55]

Answer:

The heat capacity of a sample is 37.7 J/K.

Explanation:

Given that,

Submerged temperature of tissue sample = 275 K

Mass of liquid nitrogen= 2 kg

Temperature = 70 K

Final temperature = 75 K

We need to calculate the heat

Using formula of heat

$Q=mc(T_{f}-T_{i})$

Put the value into the formula

$Q=2\times1.039\times10^{3}\times(75-70)$

$Q=10390\ J$

We need to calculate the heat capacity of a sample

Using formula of heat capacity

$\Delta S=\dfrac{Q}{T}$

Put the value into the formula

$\Delta S=\dfrac{10390}{275}$

$\Delta S=37.7\ J/K$

Hence, The heat capacity of a sample is 37.7 J/K.

7 0

3 years ago

Read 2 more answers

6A certain load and set of slings create a 20-degree angle between the load and each sling leg. Using a spreader for the same li

Otrada [13]

Solution:

The angle between the sling and the load is $20^{\circ}$

So the tension in each sling can be calculated as

$Sin \theta = Mg => T = \frac{Mg}{2Sin\theta}$

$Sin \theta=> \frac{Mg}{2Sin 20^{\circ}}$

Where

M is the mass of the load

The Horizontal reaction on the sling will be inward.

After using the spreader, the new angle between sling and load is $60^{\circ}$ , the tension in the sling will be

$T= \frac{Mg}{2 Sin 60^{\circ}}$ = $\frac{Mg}{2 Sin 20^{\circ}}$

The tension will be same as before in the sling move away through the spreader at an angle more than 90 degree the horizontal force will act opposite and will be outward

5 0

3 years ago

A graph that plots the temperature of a star against its brightness.

Ostrovityanka [42]

Answer:

C. HertzPrung Russel Diagram

Explanation:

The Hertzsprung–Russell diagram, or H–R diagram, is a plot of stellar luminosity against surface temperature. Most stars lie on the main sequence, which extends diagonally across the H–R diagram from high temperature and high luminosity to low temperature and low luminosity.

5 0

3 years ago

Small particles in an atom have an ------ charge

Ray Of Light [21]

It has a neutral charge which means it is equal.

7 0

3 years ago

Read 2 more answers

when the driver touches A Car steering wheel on a hot day heat is transferred to the driver's Hands by

Masteriza [31]

Heat is transferred to the driver's hands by conduction. The direct contact between the steering wheel and the driver's hands allows heat from molecules on the surface of the steering wheel to transfer to the molecules on the surface of the driver's hands. This is in contrast to convection (which requires a fluid in between the two surfaces that transfers heat).

5 0

3 years ago