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3 years ago

What potential difference is needed to give a helium nucleus (q=2e) 85.0 kev of kinetic energy?

1 answer:

6 0

The kinetic energy K given to the helium nucleus is equal to its potential energy, which is
$E=q \Delta V$
where q=2e is the charge of the helium nucleus, and $\Delta V$ is the potential difference applied to it.
Since we know the kinetic energy, we have
$E=K=85~keV=q \Delta V$
and from this we can find the potential difference:
$\Delta V = \frac{K}{q}= \frac{85~keV}{2e}=42.5~kV$

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Concave Mirror (PLATO)

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3 years ago

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3 years ago

Which are examples of convection currents ? Select three options.

Veseljchak [2.6K]

Answer:

(B) A pot being heated by an electric burner

(D) A radiator that emits warm air and draws in cool air

(E) A hot air balloon rising and falling in the atmosphere

These are some of the examples of the convection currents.

Explanation:

Earlier, electrons were believed to have positive charges and then electric current were discovered. But later after the invention of electric current and current which is termed to be the flow of electrons and is usually flows from negative to positive terminal. But its convention is not discarded in which current moves from positive terminal to negative and it is called convention current. The direction of current shown in the circuit is said to be the convention current.

Hence, the following are the examples of convention current.

1. Boiling water - The energy travels into the pot from the burner, boiling down the water. Then this warm water is accumulating on the top and colder one is heading down to absorb it, triggering a circular motion.

2. Radiator - Place hot air at the peak and pull cool air at the bottom.

3. Hot air balloon - The air is warmed up by a heating element within the balloon, so the air jumps upwards. This induces the balloon to increase in size due to the inside trapping of the warm air. He removes a few of the warm air when the pilot commences to dive, and cold air takes place, enabling the parachute to drop.

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3 years ago

Read 2 more answers

A jogger runs 6 km north ,5 km east then another 4km north her average speed 8 km how long will it take her to complete her run

LekaFEV [45]

The time taken to complete her run is 1.9 hr.

Explanation:

Speed is a scalar quantity and it is defined as the ratio of distance covered to the time taken to cover that distance. As distance is also a scalar quantity, so the directions given in the problem can be ignored. Thus, the distance covered by the jogger is the sum of kilometers given in problem.

Distance covered = 6+5+4 = 15 km

And the speed is given as 8 km/hr.

So the time taken will be ratio of distance to speed.

$\text { time }=\frac{\text {distance}}{\text {speed}}=\frac{15}{8}=1.9 \text { hour }$

So the jogger will take 1.9 hr to complete her run.

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4 years ago

A spacecraft flies away from the earth with a speed of 4.80×106m/s relative to the earth and then returns at the same speed. The

marta [7]

Answer:

1.1215 h

Explanation:

Δt=Δt_o/√(1-u^2/c^2)

(Δt° is the proper time in the rest frame,

Δt is the time intent measured in the second frame of reference u is the speed of the second frame with respect to the rest frame c is the speed of light )

a) the proper time is the time on spacecraft (rest frame);

Δt = 365 days = 8760 h

Δt=Δt_o/√(1-u^2/c^2)= 8761.1215 h

the difference = 8761.1215 h — 8760 h = 1.1215 h

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4 years ago