What kinds of telescopes are used to measure parallax

calculate the energy spent on spraying a drop of mercury of 1 cm radius into 10^6 droplets all of same radius. surface tension o

WARRIOR [948]

Answer:

ANS : .Energy spent on spraying = $4.3542*10^{-4}J$

Explanation:

Given:

Radius of mercury = 1cm initially ;
split into $10^{6}$ drops ;

Thus, volume is conserved.

i.e ,

$\frac{4}{3} \pi R_{o}^{3} = 10^{6}*\frac{4}{3} \pi R_{n}^{3}\\R_{n}=\frac{R_{o}}{10^{2}} = \frac{1cm}{100} = 0.01 cm$

Energy of a droplet = $T$ Δ $A$

Where ,

T is the surface tension
ΔA is the change in area

Initial energy $E_{i} = T*A_{i}\\= 0.0035 * 4 *\pi *0.01^{2}\\=4.398*10^{-6}J$

Final energy $E_{f}=10^{6}*T*A_{f}\\=10^{6}*0.0035*4*\pi *(0.0001)^2\\=4.39823*10^{-4}$

∴ .Energy spent on spraying = $=E_{f}-E{i}\\=(439.823-4.39823)*10^{-6}\\=4.3542*10^{-4}J$

ANS : .Energy spent on spraying = $4.3542*10^{-4}J$

6 0

3 years ago

Why do you think the temperature does not change much during a phase change?

11111nata11111 [884]

Answer:

It depends on where the temperature is dropping, in which body so to speak. Generally, the temperature adapts to the two bodies, for example if a hot piece of metal meets a cold one, the two will continue until they are at an equal temperature, an intermediate temperature.

3 0

3 years ago

Read 2 more answers

Which of the following processes are spontaneous? Check all that apply.

-Dominant- [34]

Answer:

(1) A hot drink cooling to room temperature.

(2) The combustion of natural gas.

Explanation:

The spontaneous process is the process in which there is a release of energy and moves towards lower energy and a more thermodynamically stable energy state. All the natural processes are spontaneous.

There are two processes which are spontaneous in the given question are:

(1) A hot drink cooling to room temperature: In this, there is a decrease in energy and also it is a natural process and we know that all the natural processes are spontaneous.

(2) The combustion of natural gas: The fire is an example of an exothermic reaction. The combustion is a combination of a decrease in energy and an increase in entropy. So, this process occurs spontaneously.

5 0

3 years ago

A box falls off of a tailgate and slides along the street for a distance of 62.5 m. Friction slows the box at –5.0 m/s2. At what

Mila [183]

Answer:

25 m/s

Explanation:

This question can be solved using equation of motion

$v^2 = u^2 + 2as$

where

v is the final velocity

u is the initial velocity

s is the distance covered while moving from initial to final velocity

a is the acceleration

_____________________________________________

Given

box moved for distance of 62.5 m

Friction slows the box at –5.0 m/s2----> this statement means that there is deceleration , speed of truck decreases by 5 m/s in every second until the box comes to rest. Friction causes this deceleration.

thus in this problem

a = -5.0 m/s2

V = 0 as body came to rest due to friction deceleration

u the initial velocity we have to find

the initial velocity of box will be the same as speed of truck, as the box was in the truck and hence box will pick the speed of truck.

so if we find speed of box, we will be able get sped of truck as well.

using equation of motion

$v^2 = u^2 + 2as\\0^2 = u^2 + 2*-5* 62.5\\0 = u^2 - 625\\u^2 = 625\\\sqrt{u^2} = \sqrt{625} \\u = 25$

Thus, initial speed with the truck was travelling was 25 m/s.

3 0

3 years ago

What is the restoring force of a spring with a spring constant of 4a and a stretched displacement of 3b? A. –7 ab B. `-7 a/b ` C

algol13

Answer:

C. -12 ab

Explanation:

The restoring force on a spring is given by Hooke's law:

$F=-kx$

where

k is the spring constant

x is the stretched (or compressed) displacement of the spring

In this problem we have:

k = 4a

x = 3b

Substituting into the equation, we find:

$F=-(4a)(3b) = -12 ab$

And the negative sign means that the direction of the force (negative) is opposite to the direction of the displacement (positive).

3 0

3 years ago