A joule, which is a unit of work, is equal to?

The nucleus of most atoms is composed of which of the following sub-atomic particles?

Blababa [14]

Answer:

protons (+ charge) & neutrons (neutral charge)

however protons has a positive charge so it determined what atom it is.

7 0

3 years ago

When a condenser discharges electricity, the instantaneous rate of change of the voltage is proportional to the voltage in the c

e-lub [12.9K]

Answer:

460.52 s

Explanation:

Since the instantaneous rate of change of the voltage is proportional to the voltage in the condenser, we have that

dV/dt ∝ V

dV/dt = kV

separating the variables, we have

dV/V = kdt

integrating both sides, we have

∫dV/V = ∫kdt

㏑(V/V₀) = kt

V/V₀ = $e^{kt}$

Since the instantaneous rate of change of the voltage is -0.01 of the voltage dV/dt = -0.01V

Since dV/dt = kV

-0.01V = kV

k = -0.01

So, V/V₀ = $e^{-0.01t}$

V = V₀ $e^{-0.01t}$

Given that the voltage decreases by 90 %, we have that the remaining voltage (100 % - 90%)V₀ = 10%V₀ = 0.1V₀

So, V = 0.1V₀

Thus

V = V₀ $e^{-0.01t}$

0.1V₀ = V₀ $e^{-0.01t}$

0.1V₀/V₀ = $e^{-0.01t}$

0.1 = $e^{-0.01t}$

to find the time, t it takes the voltage to decrease by 90%, we taking natural logarithm of both sides, we have

㏑(0.01) = -0.01t

So, t = ㏑(0.01)/-0.01

t = -4.6052/-0.01

t = 460.52 s

3 0

3 years ago

Suppose a ball is thrown vertically upwards from a position P above the ground. It rises to the highest point Q and returns to t

NikAS [45]

Answer:

Net displacement = 0

Distance traveled = 2PQ <_up and down

Explanation:

5 0

3 years ago

Maddie wanted to make a sugar-water solution to put in her hummingbird feeder. She found some sugar cubes and was about to drop

NNADVOKAT [17]

Answer:

this is a good suggestion

Explanation:

when the sugar cubes are crushed and they become a powder so its surface area increases. And as surface area is directly proportional to rate of reaction so the desired solution will be formed rapidly

3 0

3 years ago

Read 2 more answers

Imagine that asteroid A that has an escape velocity of 50 m/s. If asteroid B has twice the mass and twice the radius, it would h

padilas [110]

Answer:

The same as the escape velocity of asteorid A (50m/s)

Explanation:

The escape velocity is described as follows:

$v=\sqrt{\frac{2GM}{R}}$

where $G$ is the universal gravitational constant, $M$ is the mass of the asteroid and $R$ is the radius

and since the scape velocity is 50m/s:

$50m/s=\sqrt{\frac{2GM}{R}}$

Now, if the astroid B has twice mass and twice the radius, we have that tha mass is: $2M$

and the radius is: $2R$

inserting these values into the formula for escape velocity:

$v=\sqrt{\frac{2G(2M)}{2R} } =\sqrt{\frac{4GM}{2R} } =\sqrt{\frac{2GM}{R} }$

and we have found that $50m/s=\sqrt{\frac{2GM}{R}}$ , so the two asteroids have the same escape velocity.

We found that the expression for escape velocity remains the same as for asteroid A, this because both quantities (radius and mass) doubled, so it does not affect the equation.

The answer is

Asteroid B would have an escape velocity the same as the escape velocity of asteroid A

7 0

3 years ago