The ratio between the volumes of two spheres is 27 to 8. what is the ratio between their respective radii?

Changing the direction of current will or will not affect the strength of an electromagnet

jeka57 [31]

Answer:

he polarity of the electromagnet is determined by the direction the current. The north pole of the electromagnet is determined by using your right hand. Wrap your fingers around the coil in the same direction as the current is flowing (conventional current flows from + to -).

Explanation:

5 0

2 years ago

Read 2 more answers

momentum A proton interacts electrically with a neutral HCl molecule located at the origin. At a certain time t, the proton’s po

arlik [135]

Answer:

$\ m/s$

Explanation:

F = Force =

m = Mass of proton = $1.7\times 10^{-27\ kg$

t = Time taken = $2\times 10^{-14}\ s$

Acceleration is given by

$a=\dfrac{F}{m}\\\Rightarrow a=\dfrac{}{1.7\times 10^{-27}}\\\Rightarrow a=\ m/s^2$

$v=u+at\\\Rightarrow v=+\times 2\times 10^{-14}\\\Rightarrow v=+\times 2\times 10^{-14}\\\Rightarrow v=+\\\Rightarrow v=\ m/s$

The velocity of the proton is $\ m/s$

6 0

3 years ago

A fireboat is to fight fires at coastal areas by drawing seawater with a density of 1030 kg/m3 through a 10-cm-diameter pipe at

GaryK [48]

Answer:

50.93 m/s

199.5 kW

Explanation:

From the question, the nozzle exit diameter = 5 cm, Radius= diameter/2= 5cm/2= 2.5cm. we can convert it to metre for unit consistency= (2.5×0.01)=

0.025m

We can calculate the The cross sectional area of the nozzle as

A= πr^2

A= π ×0.025^2

= 1.9635 ×10^- ³ m²

From the question, the water is moving through the pipe at a rate of 0.1 m /s , then for the water to move through it at a seconds, it must move at

(0.1 / 1.9635 ×10^- ³ m²)

= 50.93 m/s

During the Operation of the pump, the Dynamic energy of the water= potential energy provided there is no loss during the Operation

mgh = 1/2mv²

We can make "h" subject of the formula, which is the height of required head of water

h = (1/2mv²)/mg

h= v² / 2g

h = 50.93² / (2 ×9.81)

h = 132.21m

From the question;

The total irreversible head loss of the system = 3 m,

the given position of nozzle = 3 m

the total head the pump needed=(The total irreversible head loss of the system + the position of the nozzle + required head of water )

=(3 + 3 + 132.21m)

=138.21m

mass of water pumped in a seconds can be calculated since we know that mass is a product of volume and density

Volume= 0.1m³

Density of sea water=1030 kg/m

(0.1 m^3× 1030)

= 103kg

We can calculate the Potential enegry, which is = mgh

= (103 ×9.81 × 138.21)

= 139651.5 Watts

= 139.65kW

To determine required shaft power input to the pump and the water discharge velocity

Energy= efficiency × power

But we are given efficiency of 70 percent, then

139651.5 Watts = 0.7P

=199502.18 Watts

P=199.5 kW

Therefore, the required shaft power input to the pump and the water discharge velocity is 199.5 kW

5 0

2 years ago

A ball is thrown straight up. What are the velocity and acceleration of the ball at the highest point in its path?

zubka84 [21]

Answer:

b. v = 0, a = 9.8 m/s² down.

Explanation:

Hi there!

The acceleration of gravity is always directed to the ground (down) and, near the surface of the earth, has a constant value of 9.8 m/s². Since the answer "b" is the only option with an acceleration of 9.8 m/s² directed downwards, that would solve the exercise. But why is the velocity zero at the highest point?

Let´s take a look at the height function:

h(t) = h0 + v0 · t + 1/2 g · t²

Where

h0 = initial height

v0 = initial velocity

t = time

g = acceleration due to gravity

Notice that the function is a negative parabola if we consider downward as negative (in that case "g" would be negative). Then, the function has a maximum (the highest point) at the vertex of the parabola. At the maximum point, the slope of the tangent line to the function is zero, because the tangent line is horizontal at a maximum point. The slope of the tangent line to the function is the rate of change of height with respect to time, i.e, the velocity. Then, the velocity is zero at the maximum height.

Another way to see it (without calculus):

When the ball is going up, the velocity vector points up and the velocity is positive. After reaching the maximum height, the velocity vector points down and is negative (the ball starts to fall). At the maximum height, the velocity vector changed its direction from positive to negative, then at that point, the velocity vector has to be zero.

8 0

3 years ago

Boiling water is a common method used to sterilize water that may be contaminated. subjecting microbes to such high temperatures

GaryK [48]

Boiling water is a common method used to sterilize water that may be contaminated. subjecting microbes to such high temperatures is an example of a(n) microbicidal technique.

A substance that eliminates microorganisms (such as bacteria) is known as microbicide and the techniques that involve destruction of microbes are known as microbicidal techniques.

The pathogen biofilm was effectively destroyed by the combined microbicidal effects of hot water (50, 60, or 70 °C) and 2% citric acid. It was discovered that the combination of hot water and citric acid caused sub-lethally harmed cells.

A fairly easy way to disinfect water is to boil it. The majority of dangerous organisms, notably viruses and bacteria that cause waterborne infections, are killed when water is heated to a high temperature of 100°C. The water must boil for at least 20 minutes in order to be most effective.

Hence, water that may be polluted is frequently sterilized by boiling. Using such high temperatures to kill germs is an example of a microbicidal method.

Learn more about Sterilization techniques here brainly.com/question/13062351

#SPJ4

7 0

1 year ago