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4 years ago

A polar bear swims 3.5 m/s, how long will it take the polar bear to swim 20 m?

Physics

1 answer:

ycow [4]4 years ago

4 0

Given:

Speed = 3.5 m/s

Distance = 20 m

To find:

Time taken

Solution:

Speed = Distance/Time

Time = Distance/Speed

Substituting given values, we get

Time = 20/3.5

<em>Time = 5.714 seconds</em>

Please mark Brainliest if this helps!

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4.) What are examples of physical and chemical properties?

lubasha [3.4K]

Answer:

Some physical properties are odor (Sewage smell), and melting and boiling point (boiling water melting ice).

Some chemical properties are flammability (burning wood), and oxidation (rotting apple).

Explanation:

7 0

4 years ago

Suppose a tank filled with water has a liquid column with a height of 19 meter. If the area is 2 square meters 2m squared, what’

ycow [4]

Answer:

372,400 N

Explanation:

The volume of the column is ...

V = Bh = (2 m^2)(19 m) = 38 m^3

If we assume the density is 1000 kg/m^3, then the mass of the water is ...

M = ρV = (1000 kg/m^3)(38 m^3) = 38,000 kg

The force of gravity on that mass is ...

F = Mg = (38,000 kg)(9.8 m/s^2) = 372,400 N

4 0

3 years ago

A current of 0.001 A can be felt by the human body. 0.005 A can produce a pain response. 0.015 A can cause a loss of muscle cont

lys-0071 [83]

Answer:

In summary, it is safe to handle this voltage with dry hands because the current value that you pass through the body is smaller than its underestimated sensitivity.

Explanation:

The current flowing through your system is described by Ohm's law

V = I R

where I is the current, V the voltage and R the resistance

in this case three barateras are taken in series giving a total voltage of V = 4.5 V the typical resistance values of dry skin is R = 1000 000Ohm and the resinification of wet skin is R = 100000 ohm

let's calculate the current flowing

I = V / R

I = 4.5 / 1000000

I = 4.5 10⁻⁶ A

this is the current with dry hands, we see that much less than the value that allows to feel a painful response by the body

If the skin is

I = 4,5 / 100,000

I = 4.5 10⁻⁵ A

This value is small, but it is close to the pain threshold, but it is in the range of slight discomfort.

In summary, it is safe to handle this voltage with dry hands because the current value that you pass through the body is smaller than its underestimated sensitivity.

7 0

3 years ago

The following table lists the work functions of a few commonmetals, measured in electron volts.

steposvetlana [31]

Answer:

Lithium

Explanation:

The equation for the photoelectric effect is

$\frac{hc}{\lambda}= \phi + K_{max}$

where

$\frac{hc}{\lambda}$ is the energy of the incident photon, with

h being the Planck constant

c is the speed of light

$\lambda$ is the wavelength of the photon

$\phi$ is the work function of the metal (the minimum energy needed to extract the photoelectron from the metal)

$K_{max}$ is the maximum kinetic energy of the emitted photoelectrons

In this problem, we have

$\lambda= 190 nm = 1.9\cdot 10^{-7}m$ is the wavelength of the incident photon

$K_{max}=4.0 eV$ is the maximum kinetic energy of the electrons

First of all we can find the energy of the incident photon

$E=\frac{(6.63\cdot 10^{-34} Js)(3\cdot 10^8 m/s)}{1.90\cdot 10^{-7} m}=1.05\cdot 10^{-18} J$

Converting into electronvolts,

$E=\frac{1.05\cdot 10^{-18} J}{1.6\cdot 10^{-19} J/eV}=6.6 eV$

So now we can re-arrange the equation of the photoelectric effect to find the work function of the metal

$\phi = E-K_{max}=6.6 eV - 4.0 eV=2.6 eV$

So the metal is most likely Lithium, which has a work function of 2.5 eV.

3 0

3 years ago

You have a 10 volt parallel circuit, with 2 resistors on it. What is the voltage across the first resistor? Across the second?

zheka24 [161]

What is the value of the resistors? There are many types of resistors with different values for how much resistance they provide

Edit: My bad. Where are the resistors located

3 0

4 years ago

Read 2 more answers