A joule is equivalent to a

Red light is bent the least of all colors as it passes through a prism. What does this tell you about red light? It has a short

Alik [6]

Answer:

Longest wavelength, lowest intensity

Explanation:

7 0

3 years ago

Ask Your Teacher In the air over a particular region at an altitude of 500 m above the ground, the electric field is 120 N/C dir

strojnjashka [21]

Answer:

$1.475\times 10^{-13}\ C/m^3$

Explanation:

$\epsilon_0$ = Permittivity of free space = $8.85\times 10^{-12}\ F/m$

A = Area

h = Altitude = 600 m

Electric flux through the top would be

$-110A$ (negative as the electric field is going into the volume)

At the bottom

$120A$

Total flux through the volume

$\phi=120-110\\\Rightarrow \phi=10A$

Electric flux is given by

$\phi=\dfrac{q}{\epsilon_0}\\\Rightarrow q=\phi\epsilon_0\\\Rightarrow q=10A\epsilon_0$

Charge per volume is given by

$\rho=\dfrac{q}{v}\\\Rightarrow \rho=\dfrac{10A\epsilon_0}{Ah}\\\Rightarrow \rho=dfrac{10\epsilon_0}{h}\\\Rightarrow \rho=\dfrac{10\times 8.85\times 10^{-12}}{600}\\\Rightarrow \rho=1.475\times 10^{-13}\ C/m^3$

The volume charge density is $1.475\times 10^{-13}\ C/m^3$

7 0

3 years ago

A 48.0-kg skater is standing at rest in front of a wall. By pushing against the wall she propels herself backward with a velocit

Kipish [7]

Answer:

F = 47.6 N

Explanation:

Newton's 2nd law can be expressed as the rate of change of the total momentum, respect of time, as follows:

$F = \frac{\Delta p}{\Delta t}$

So, in order to find the average force exerted by the skater on the wall, we can find the change in momentum due to the force exerted by the wall (which is equal and opposite to the one exerted by the skater), and divide it by the time interval , as follows:

$F_{wall} = \frac{\Delta p}{\Delta t} =\frac{(48.0 kg*(-1.06m/s)}{1.07s} = -47.6 N$

⇒ Fsk = 47.6 N (normal to the wall)

3 0

3 years ago

A bus took 8 hours to travel 639 km. For the first 5 hours, it

vladimir1956 [14]

Answer:

93 km/h

Explanation:

Given that a bus took 8 hours to travel 639 km. For the first 5 hours, it travelled at an average speed of 72 km/h

Let the first 5 hours journey distance = F

From the formula of speed,

Speed = distance/time

Substitute speed and time

72 = F/5

F = 72 × 5 = 360 km

The remaining distance will be:

639 - 360 = 279km

The remaining time will be:

8 - 5 = 3 hours

Speed = 279/3

Speed = 93 km/h

Therefore, the average speed for the remaining time of the journey is equal to 93 km/h

8 0

3 years ago

A student drops a 1.5 kg rock off of a 4.0 m tall bridge. The speed of the rock just before it hits the water below is 6 m/s. Ho

olga nikolaevna [1]

Answer:

Energy due to air resistance = 31.8 Joules

Explanation:

According to the law of conservation of energy, energy can neither be created nor destroyed but can be transformed from one form to another

Kinetic Energy + Energy due to air resistance = Potential energy..........(1)

If there is no energy loss due to air resistance, potential energy = kinetic energy

mass, m = 1.5 kg

height, h = 4.0 m

speed, v = 6 m/s

Kinetic energy = 0.5 mv²

Kinetic energy = 0.5 * 1.5 * 6²

Kinetic energy = 27 Joules

Potential Energy = mgh

Potential energy = 1.5 * 9.8 * 4

Potential energy = 58.8 Joules

From equation (1)

27 + Energy due to air resistance = 58.8

Energy due to air resistance = 58.8 - 27

Energy due to air resistance = 31.8 Joules

8 0

2 years ago

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