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ki77a [65]
3 years ago
8

A 1500-W electric heater is plugged into the outlet of a 120-V circuit that has a 20-A circuit breaker. You plug an electric hai

r dryer into the same outlet. The hair dryer has power settings of 600 W, 900 W, 1200 W, and 1500 W. You start with the hair dryer on the 600-W setting and increase the power setting until the circuit breaker trips.
What power setting caused the breaker to trip?A) 600 WB) 900 WC) 1200 WD) 1500 W
Physics
1 answer:
Korolek [52]3 years ago
8 0

Answer:

b) 900 W

Explanation:

The breaker trips when the current is equal to 20 A. The power (P) is the ddp (V) multiplied by the current. So, for the electric heater, the current is:

P = V*i

1500 = 120*i

i = 12.5 A

So, to become in 20 A, it's needed 7.5 A, which must come from the hairdryer. Its power must be:

P = 120*7.5

P = 900 W

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What does the spinal cord on a sheep brain do
Leviafan [203]

Cerebellum: controls balance and muscle coordination; located caudal to the cerebrum in the sheep brain. ... Gray matter: areas of the brain and spinal cord containing neuronal cell bodies, dendrites, and unmyelinated axons. Found in the cerebral cortex of the brain and inner area of the spinal cord

7 0
3 years ago
Read 2 more answers
At a given instant the bottom A of the ladder has an acceleration aA = 4 f t/s2 and velocity vA = 6 f t/s, both acting to the le
Nana76 [90]

Answer:

Acceleration=24.9ft^2/s^2

Angular acceleration=1.47rads/s

Explanation:

Note before the ladder is inclined at 30° to the horizontal with a length of 16ft

Hence angular velocity = 6/8=0.75rad/s

acceleration Ab=Aa +(Ab/a)+(Ab/a)t

4+0.75^2*16+a*16

0=0.75^2*16cos30°-a*16sin30°---1

Ab=0+0.75^2sin30°+a*16cos30°----2

Solving equation 1

(0.75^2*16cos30/16sin30)=angular acceleration=a=1.47rad/s

Also from equation 2

Ab=0.75^2*16sin30+1.47*16cos30=24.9ft^2/s^2

6 0
3 years ago
The eye is actually a multiple-lens system, but we can approximate it with a single-lens system for most of our purposes. When t
hram777 [196]

Explanation:

Given that,

The optical power of the equivalent single lens is 45.4 diopters.

(a) The relationship between the focal length and the focal length is given by:

f=\dfrac{1}{P}

f=\dfrac{1}{45.4}

f = 0.022 m

or

f = 2.2 cm

(b) We need to find how far in front of the retina is this "equivalent lens" located. It is given by using lens formula as :

\dfrac{1}{v}-\dfrac{1}{u}=\dfrac{1}{f}

Here, u = infinity

\dfrac{1}{v}=\dfrac{1}{2.2}

v = 2.2 cm

So, at 2.2 cm in front of the retina is this "equivalent lens" located.

Hence, this is the required solution.

5 0
3 years ago
I've got an energy and work problem. The premise of the problem is:
Alenkasestr [34]
Refer to the diagram shown below.

μ =  the coefficient of dynamic friction between the crate and the ramp.

1. The applied force of F acts over a distance, d.
    The work done is F*d.

2. The component of the weight of the crate acting down the ramp is
    mg sin(30) = 0.5mg. 
    The work done by this force is 0.5mgd.

3. The normal force is N = mgcos(30) = 0.866mg.
     This force is perpendicular to the ramp, therefore the work done is zero.

4. The frictional force is μN = μmgcos(30) = 0.866μmg.
    The work done by the frictional force is 0.866μmgd.

5. The total force acting on the crate up the ramp is
     F - mgsin(30) - μmgcos(30) = F - mg(0.5 - 0.866μ) 

6. The work done on the crate by the total force is
    d*(F - 0.5mg - 0.866μmg)

7 0
3 years ago
g A motorist traveling at 30.0 m/s passes a stationary police car. The police car gives chase 2.0 s later, accelerating at 5.0 m
Sedaia [141]

The time for the police car to catch up with the speeding motorist is 7.6 seconds.

<h3>What time will the police car catch up with the speeding motorist?</h3>

The police car and the motorist will cover equal distances.

Let the distance covered be d.

Distance covered by the motorist  = speed * time

time = t, speed = 30 m/s

d = 30t

Distance covered by the police car = acceleration * (time)

time = t - 2, acceleration = 5.0 m/s²

d = 5(t-2)²

d = 5(t² - 4t + 4)

d = 5t² - 20t + 20

Equating the two equations for distance

5t² - 20t + 20 = 30t

5t² - 50t + 20 = 0

Solving for t using the quadratic formula:

t = 9.6 second or 0.4 seconds

Since t > 2, t = 9.6 seconds

t - 2 = 9.6 - 2

t - 2 = 7.6 seconds

Therefore, the time for the police car to catch up with the speeding motorist is 7.6 seconds.

Learn more about distance and acceleration at: brainly.com/question/14344386

#SPJ1

4 0
1 year ago
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