All categories

3 years ago

Help!! Thank You!! Potassium has 19 protons. How many electrons does a neutral potassium atom have?

2 answers:

8 0

A neutral atom... no matter what the element... has the same number of protons and electrons. In this case, 19 electrons are needed.

Alisiya [41]3 years ago

7 0

19, because the number of protons and electrons are the same!

You might be interested in

A 50.0 kg object rests on a horizontal surface. The coefficient of static friction between the box and the surface is 0.300 and

MariettaO [177]

Answer:

$f=140\ N$

Explanation:

Given:

mass of the object on a horizontal surface, $m=50\ kg$

coefficient of static friction, $\mu_s=0.3$

coefficient of kinetic friction, $\mu_k=0.2$

horizontal force on the object, $F=140\ N$

Now the value of limiting frictional force offered by the contact surface tending to have a relative motion under the effect of force:

$F_s=\mu_s.N$

where:

$N=$ normal force of reaction acting on the body= weight of the body

$F_s=0.3\times (50\times 9.8)$

$F_s=147\ N$

As we know that the frictional force acting on the body is always in the opposite direction:

So, the frictional force will not be at its maximum and will be equal in magnitude to the applied external force and hence the body will not move.

so, the frictional force will be:

$f=140\ N$

8 0

3 years ago

A car with a mass of 1100kg is moving in a circular curve at a uniform velocity of 15m/s

Dmitrij [34]

Centripetal force = (mv^2)/r
so r = (mv^2)/ force = 246500 / 1100 = 224 m

7 0

2 years ago

A 300 kg car initially travels with a velocity of 20 m/s to the right. A net force F acts on the car for 5 s, which causes the v

hram777 [196]

Answer:

600N.

Explanation:

From the question, we are to calculate the net force acting on the car.

According to Newton's second law of motion:

F = ma

m is the mass of the car

a is the acceleration = change in velocity/Time

a = v-u/t

F = m(v-u)/t

v is the final velocity = 30m/s

u is the initial velocity = 20m/s

t is the time = 5secs

m = 300kg

Get the net force:

Recall that: F = m(v-u)/t

F = 300(30-20)/5

F = 60(30-20)

F = 60(10)

F = 600N

Hence the net force acting on the car is 600N.

3 0

3 years ago

A silver wire with resistivity 1.59 × 10-8 Ω-m carries a current density of 4.0 A/mm2, What is the magnitude of the electric fie

Nat2105 [25]

Answer:

Electric field, E = 0.064 V/m

Explanation:

It is given that,

Resistivity of silver wire, $\rho=1.59\times 10^{-8}\ \Omega-m$

Current density of the wire, $J=4\ A/mm^2=4\times 10^6\ A/m^2$

We need to find the magnitude of the electric field inside the wire. The relationship between electric field and the current density is given by :

$E=J\times \rho$

$E=4\times 10^6\times 1.59\times 10^{-8}$

E = 0.0636 V/m

E = 0.064 V/m

So, the magnitude of electric field inside the wire is 0.064 V/m. Hence, this is the required solution.

6 0

3 years ago

Hydroelectric plants are used to produce electricity. Electric generators are used in such plants that are linked to water-wheel

svp [43]

Hydroelectric plants are used to produce electricity is the statement that best explains the relationship between energy and motion.

<h3>Explains the relationship between energy and motion in the process?</h3>

There is direct relationship between energy and motion in the process because if we increase the motion of the turbines, more electricity is produced in the generator and vice versa.

So we can conclude that the relationship between energy and motion in the process is directly proportional to each other.

Learn more about energy here: brainly.com/question/13881533

#SPJ1

5 0

2 years ago