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3 years ago

14

A reaction in which small nuclei combine to form a heavier nucleus is called ____. a. fission c. background radiation b. a chemi

cal reaction d. fusion

1 answer:

Stels [109]3 years ago

8 0

<span>The correct answer is D) fusion. In fact, nuclear fusion occurs when two (or more) small nuclei combine to form a heavier nucleus. In the process, a large amount of energy is released, according to Einstein's formula </span> $E=mc^2$ <span>, where m is the mass converted into energy in the reaction. An example of nuclear fusion is the fusion of two nuclei of hydrogen into a nucleus of helium-4.</span>

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How does changing the lengthy but not the height of an inclined plane affect the work done to lift a load? PLZ HELP ME NOW'

Serhud [2]

Answer: Work Done would remain same.

Let us assume that the velocity is constant while taking the load up the inclined plane. Then, the kinetic energy would remain the same. This is because kinetic energy is dependent on velocity $(K.E.=\frac{1}{2}mv^2)$ . If that is constant, the kinetic energy would remain same. The potential energy is dependent on the height $(P.E.=mgh)$ . If the height is changed, then potential energy varies. In the question, it is mentioned that without changing the height, the length of the inclined plane is changed. Therefore, the potential energy would be same as before.

We know, work done is equal to potential energy plus kinetic energy. Since there is no change in any of these, the required work done would not change.

4 0

3 years ago

A piston-cylinder device contains Helium gas initially at 150 kPa, 20 o C, and 0.5m 3 . The helium is now compressed in a polytr

Molodets [167]

Answer:

Explanation:

Given

$P_1=150 kPa$

$T_1=20^{\circ}C$

$V_1=0.5 m^3$

$T_2=140^{\circ}C$

$P_2=400 kPa$

R for Helium $R=2.076$

$c_v=3.115 kJ/kg-K$

mass of gas $m=\frac{P_1V_1}{RT_1}$

$m=\frac{150\times 0.5}{2.076\times 293}$

$m=0.123 kg$

Similarly $V_2$ can be found

$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$

$V_2=0.264 m^3$

Work done $W=\int_{V_1}^{V_2}PdV$

$W=\frac{P_2V_2-P_1V_1}{n-1}$

$W=\frac{mR(T_2_T_1)}{n-1}$

Since it is a polytropic Process

therefore $PV^n=c$

$P_1V_1^n=P_2V_2^n$

$(\frac{V_1}{V_2})^n=\frac{P_2}{P_1}$

$(\frac{0.5}{0.264})^n=\frac{400}{150}$

$n=\frac{\ln 2.66}{\ln 1.893}$

$n=1.533$

$W=\frac{0.123\times 2.076(140-20)}{1.533-1}$

$W=57.48 kJ$

From Energy balance

$E_{in}-E_{out}=\Delta E_{system}$

Neglecting kinetic and Potential Energy change

$Q_{in}+W_{in}=change\ in\ Internal\ Energy$

Change in Internal Energy $\Delta U=u_2-u_1$

$\Delta U=mc_v(T_2-T_1)$

$\Delta U=0.123\times 3.115(140-20)$

$\Delta U=45.977 kJ$

$Q_{in}+57.48=45.977$

$Q_{in}=-11.50 kJ$

i.e. Heat is being removed

3 0

3 years ago

A potential difference of 1.20 V will be applied to a 33.0 m length of 18-gauge copper wire (diameter = 0.0400 in.). Calculate (

Nostrana [21]

Answer:A) Current = 1.739A, B)current density, J = 2.147x10^6 A/m2

magnitude of electric field , E = 0.036 N/C

)rate of thermal energy, P =2.086W

Explanation:

Resistance = R = ρL/A

But the cross-section area of the wire. is given as

Diameter / 2 = 0.04/2 =0.02in to m = 0.02 / 39.37= 0.000508

A = πr^2 = π x 0.000508^2 = 8.10 x 10^-7

since resistivity of copper,ρ= 17x10-9 ohm.m

so resistance is R = ρL/A

17x10-9 x 33 / 8.1x10-7

= 0.69 ohm.

A) Current = I = Voltage /Resistance =1.20/0.69 =1.739A

B)current density, J = Current /Area

= 1.739/8.1x10-7

= 2.147x10^6 A/m2

c)magnitude of electric field , E = Current density x resistivity =J ρ

E = 2.147 x 10^6 x 17 x 10^-9

E = 0.036 N/C

D)rate of thermal energy, P = I² R =1.739² X 0.69

=2.086W

6 0

3 years ago

When passing through a lock, which light means âapproach the lock under full control?â?

vekshin1

The locks referred to here are the elevators that are used to transport boats safely from one water level to another in dams. These two varying water depths allow river traffic to operate The attached picture shows how boats enter locks in dam sites.

To regulate traffic, there are traffic lights that signal boatmen to adjust their speed when approaching the lock. The red light means to stop and to steer clear away from the lock to allows the boats inside to exit. The green light signals to enter the lock. Lastly, the amber light means approach the lock at a safe speed and under full control.

6 0

3 years ago

Which is found farthest from the center of an atom?

xxTIMURxx [149]

Electron

Hope this helps

5 0

3 years ago