- A man pushes his car with a force of 100.0 N through a distance of 20.0 m how much work does the man

A pulsar is a rapidly rotating neutron star that emits a radio beam the way a lighthouse emits a light beam. We receive a radio

DanielleElmas [232]

Answer:

$\alpha =-2.2669642\times^{-10}rad/s^2$

Explanation:

Angular acceleration is defined by $\alpha =\frac{\Delta \omega}{\Delta t}=\frac{\omega_f-\omega_i}{\Delta t}$

Angular velocity is related to the period by $\omega=\frac{2\pi}{T}$

Putting all together:

$\alpha =\frac{\frac{2\pi}{T_f}-\frac{2\pi}{T_i}}{\Delta t}=\frac{2\pi}{\Delta t}(\frac{1}{T_f}-\frac{1}{T_i})$

Taking our initial (i) point now and our final (f) point one year later, we would have:

$\Delta t=1\ year=(365)(24)(60)(60)s=31536000
s$

$T_i=0.0786s$

$T_f=0.0786s+7.03\times10^{-6}s$

So for our values we have:

$\alpha =\frac{2\pi}{\Delta t}(\frac{1}{T_f}-\frac{1}{T_i})=\frac{2\pi}{31536000s}(\frac{1}{0.0786s+7.03\times10^{-6}s}-\frac{1}{0.0786s})=-2.2669642\times^{-10}rad/s^2$

Where the minus sign indicates it is decelerating.

8 0

3 years ago

A 120 V potential difference is applied to a space heater that dissipates 674 W during operation. (a) What is its resistance dur

Annette [7]

Answer:

(a) 21.36 ohms

(b) 5.62 A

Explanation:

Parameters given:

Potential difference, V = 120 V

Power, P = 674 W

(a) Power is given as:

P = V²/R

Where R is resistance

=> R = V²/P

R = 120²/674

R = 14400/674

R = 21.36 ohms

(b) Power is also given as:

P = I*V

Where I = Current (time rate of flow of Electric charge)

=> I = P/V

I = 674/120

I = 5.62 A

6 0

3 years ago

Read 2 more answers

A turn signal lamp must be visible in normal sunlight at a distance of at least ______ feet from the front and rear of the vehic

kaheart [24]

Answer:

500; 300 feet.

Explanation:

A turn signal lamp can be defined as an amber blinking lamp which indicates a driver's intent to change direction. It is extremely important that drivers gives a turn signal (flashing light) on the side toward which he or she is turning either left or right.

Simply stated, the turn signal lamp indicate the driver's intent to turn either leftward or rightward by displaying flashing lights to the front and rear of his or her vehicle.

A turn signal lamp must be visible in normal sunlight at a distance of at least 500 feet from the front and rear of the vehicle if the vehicle is at least 80 inches wide, and at least 300 feet from front and rear of the vehicle if the vehicle is less than 80 inches wide according to the transportation traffics code.

8 0

3 years ago

A refrigerator having a power rating of 350W operates for 12 hours a day. calculate the cost of electrical energy to operate it

rodikova [14]

Answer:

See the answers below.

Explanation:

The cost of energy can be calculated by multiplying each given value, a dimensional analysis must be taken into account in order to calculate the total value of the cost in Rs.

$Cost=0.350[kW]*12[\frac{hr}{1day}]*30[days]*4.5[\frac{Rs}{kW*hr} ]=567[Rs]$

The fuse can be calculated by knowing the amperage.

$P=V*I$

where:

P = power = 350 [W]

V = voltage = 240 [V]

I = amperage [amp]

Now clearing I from the equation above:

$I=P/V\\I=350/240\\I=1.458[amp]$

The fuse should be larger than the current of the circuit, i.e. about 2 [amp]

3 0

3 years ago

NASA is giving serious consideration to the concept of solar sailing. A solar sailcraft uses a large, low- mass sail and the ene

RUDIKE [14]

Answer:

d. The sail should be reflective because in this case the momentum transferred to the sail per unit area per unit time is larger than for absorbing sail, therefore the radiation pressure is larger for the reflective sail.

Explanation:

Let us take the momentum of a photon unit as u

we know that the rate of change of momentum is proportional to the force exerted.

For a absorbing surface, the photon is absorbed, therefore the final momentum is zero. From this we can say that

F = (u - 0)/t = u/t

for a unit time, the force is proportional to the momentum of the wave due to its energy density. Therefore,

F = u

For a reflecting surface, the momentum of the wave strikes the sail and changes direction. Since we know that the speed of light does not change, then the force is proportional to

F = (u - (-u))/t = 2u/t

just as the we did above, it becomes

F = 2u.

From this we can see that the force for a reflective sail is twice of that for an absorbing sail, and we know that the pressure is proportional to the force for a given area. From these, we conclude that the sail should be reflective because in this case the momentum transferred to the sail per unit area per unit time is larger than for absorbing sail, therefore the radiation pressure is larger for the reflective sail.

3 0

3 years ago