Move 13 m west and then 8 m east?HELP!!!

Can physics measure the work a porter does? What do you need to know to measure a porters work? What produces work, and how is p

stiv31 [10]

Answer:

No

Explanation:

According to physics, the work done by porter is zero but in reality porter gets tired as muscular energy is being used up.

In physics, work is the dot product of force and displacement. when the porter moves with the luggage, the weight act downwards while the porter moves forward. The angle between force and displacement is 90°. Thus, work done by the porter is zero.

The muscles are doing work in this case which is not calculated in physics.

Power is the rate of energy consumed during the work.

3 0

3 years ago

A softball is thrown perfectly vertically (straight-up) at 18 m/s.

inessss [21]

Answer:

a) y = 16.51 [m]

b) t = 1.83 [s]

Explanation:

To solve this problem we must use two kinematics equations, the first to determine the height to which the ball reaches, and the second equation to determine how long it lasts in the air.

$v_{f} ^{2}= v_{i} ^{2} - (2*g*t)\\$

where:

Vf = final velocity = 0

Vi = initial velocity = 18 [m/s]

g = gravity acceleration = 9.81[m/s^2]

t = time [s]

Note: the negative sign of the Equation indicates that the acceleration of gravity acts in the opposite direction to the movement of the ball. The final velocity is zero, since the ball reaches its maximum altitude when the velocity is zero.

Now replacing:

0 = (18)^2 - (2*9.81*y)

y = 16.51 [m]

b)

$v_{f} = v_{i} - (g*t)$

0 = 18 - (9.81*t)

t = 1.83 [s]

8 0

3 years ago

Light of a given wavelength is used to illuminate the surface of a metal, however, no photoelectrons are emitted. in order to ca

solniwko [45]

We will decrease the wavelength of light in order to cause electrons to be ejected from the surface of this metal.

We have a Light of a given wavelength that is used to illuminate the surface of a metal, however, no photoelectrons are emitted.

We have to find out what can we do in order to cause electrons to be ejected from the surface of this metal.

<h3>What is Photoelectric Effect ?</h3>

The emission of electrons from the surface of the metal when the light of specific frequency (greater than the threshold frequency) falls over it is called photoelectric effect.

Light consists of photons. The energy associated with the photons is used to emit out the electrons from the surface of metal. We know that - Energy can neither be created nor be destroyed and it can only be transferred from one body to another. Hence, the energy of these moving photons is used to emit electrons from the metal surface. The energy associated with the photon is given by -

E = hμ

Where - μ is the frequency of light an h is Planck's constant.

Now, we can see that the energy of the photon is directly proportional to the frequency of light. The minimum frequency required to eject the electron from the metal surface is called Threshold frequency. Thus, we can emit the electron from the metal surface by using the light of frequency greater than threshold frequency.

Hence, we will increase the frequency of light in order to cause electrons to be ejected from the surface of this metal

To solve more questions on Photoelectric Effect, visit the link below -

brainly.com/question/9260704

#SPJ4

8 0

2 years ago

Acetone is a flammable solvent used in the making of plastics. The density is 790kg/m3. to convert 790kg/m3 to g/cm3

Artist 52 [7]

Answer: 0.790 g/cm3

Explanation:

The density of acetone is 790 Kg/m3.

To convert from Kg to g we multiply by 1000 (1 Kg = 1000 g)

To convert from m3 to cm3 we multiply by 10∧6

So, The density of acetone in (g/cm3) = (790 x 1000) / (10∧6) = 0.79 g/cm3

4 0

3 years ago

Can anybody write a short poem about friction

Luden [163]

Answer:

you will be the clouds
and I will be the sky.
you will be the ocean
and I will be the shore.
you will be the trees
and I will be the wind.

whatever we are, you and I will always collide.

There you go! Let me know if it helped.
:)

8 0

2 years ago