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2 years ago

Explain why mercury is rarely used in modern thermometers

1 answer:

3 0

Answer: Mercury is rarely used in thermometers that take body temperatures because it is toxic, accidentally if by any chance a thermometer breaks orleaky, mercury gets inside body and can cause harm.

Explanation:

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For a satellite of mass mS in a circular orbit of radius rS around the Earth, determine its kinetic energy, K . Express your ans

agasfer [191]

Since it is asking you to find the kinetic energy in relation to the mass, radius, mechanical energy (total energy), and constants, you will need to setup an equation first to "find" the Mechanical Energy, so that we can then solve for the kinetic energy, as from my experience with high school physics, there is only the graviational potential energy equation and force in relation to celestial bodies.

Knowing the ME is the total energy, we add up the energies of the system. Since it is being influenced by the Earth, as per the problem stating the satellite has circular orbit around the Earth, we know there is gravitational potential. Since it is orbiting, we can assume some type of velocity. Nothing else that we need to worry about should be occuring at this level of physics, leaving you with

ME= Ug+K

from here we solve for K, as plugging in could get confusing and messy at the moment.

ME-Ug=K

now using the equations presumably given in class, if not then using this equation, we can find the Ug

Ug=(-(Gm*M)/r) note that M is the mass of the Earth and m is the satellite

this should give us

ME-(-(GmM)/r)=K

since there is a negative being subracted, we can change that to

ME+(GmM)/r=K

I believe this should be fine, as the Earth's mass is constant, but if not, then all you need to figure left is how to get rid of the M in the equation, as the rest of the terms and constants are for sure within the requirements.

8 0

3 years ago

A 0.140-kg baseball is dropped from rest. It has a speed of 1.20 m/s just before it hits the ground, and it rebounds with an upw

irga5000 [103]

Answer:

22 N upward

Explanation:

From the question,

Applying newton's second law of motion

F = m(v-u)/t....................... Equation 1

Where F = Average force exerted by the ground on the ball, m = mass of the baseball, v = final velocity, u = initial velocity, t = time of contact

Note: Let upward be negative and downward be positive

Given: m = 0.14 kg, v = -1.00 m/s, u = 1.2 m/s, t = 0.014 s

Substitute into equation 1

F = 0.14(-1-1.2)/0.014

F = 0.14(-2.2)/0.014

F = 10(-2.2)

F = -22 N

Note the negative sign shows that the force act upward

6 0

3 years ago

What are three major types of fungi and an example of each.

Nesterboy [21]

1) yeasts example is Sacchromyces Cerevisiae which is a baker's or brewer's yeast

2) molds example is Rhizopus a type of mold that appears on old bread

3) mushrooms example is Amanita Phalloides also known as the "Death Cap " is a very poisonous mushroom and should not be ingested

3 0

3 years ago

Read 2 more answers

The aurora is caused when electrons and protons, moving in the earth’s magnetic field of ≈5.0×10−5T, collide with molecules of t

ollegr [7]

Answer:

8.79*10^6 rad/s

Explanation:

To find the frequency of the circular orbit for an electron you use the following expression, for the radius of the trajectory of an electron, that travels trough a constant magnetic field:

$r=\frac{mv}{qB}$ (1)

r: radius of the trajectory

m: mass of the electron = 9.1*10^-31 kg

v: speed of the electron = 1.0*10^6 m/s

q: charge of the electron = 1.6*10^-19 C

B: magnitude of the magnetic field = 5.0*10^-5 T

You use the fact that the angular frequency in a circular motion is given by:

$\omega=\frac{v}{r}$

Then, you solve the equation (1) in order to obtain v/r:

$\frac{v}{r}=\omega=\frac{qB}{m}$

Finally, you replace the values of the parameters:

$\omega=\frac{(1.6*10^{-19}C)(5.0*10^{-5}T)}{9.1*10^{-31}kg}\\\\\omega=8.79*10^6\frac{rad}{s}$

hence, the angular frequency is 8.79*10^6 rad/s

The frequency is:

$f=2\pi \omega=5.5*10^7Hz$

5 0

3 years ago

two resistors of 20 ohm each are connected in a parallel with a battery of 10V. The total current passing through circuit is

Varvara68 [4.7K]

Answer:

1 Ampere.

Explanation:

From the question given above, the following data were obtained:

Resistor 1 (R₁) = 20 ohm

Resistor (R₂) = 20 ohm

Voltage (V) = 10 V

Current (I) =?

Next, we shall determine the equivalent resistance in the circuit. This can be obtained as follow:

Resistor 1 (R₁) = 20 ohm

Resistor (R₂) = 20 ohm

Equivalent Resistance (R) =?

Since the resistors are in parallel connection, the equivalent resistance can be obtained as follow:

R = (R₁ × R₂) / (R₁ + R₂)

R = (20 × 20) / (20 + 20)

R = 400 / 40

R = 10 ohm

Finally, we shall determine the total current in the circuit. This can be obtained as illustrated below:

Voltage (V) = 10 V

Equivalent Resistance (R) = 10 ohm

Current (I) =?

V = IR

10 = I × 10

Divide both side by 10

I = 10 / 10

I = 1 Ampere

Therefore, the total current in the circuit is 1 Ampere.

3 0

2 years ago