In the circuit shown, the galvanometer shows zero current. The value of resistance R is :

An observer standing near a window 5 m high observe that an object falling downwards is passing across the window in 0.5 s. Find

Valentin [98]

Answer:

Explanation:

An object in free fall, NOT experiencing parabolic motion, has an equation of

$h(t)=\frac{1}{2} gt^2+h_0$ which says:

The height of an object with respect to time in seconds is equal to the pull of gravity times time-squared plus the height from which it was dropped. Normally we use -9.8 for gravity but you said to use 10, so be it.

For us, h(t) is 5 because we are looking for the height of the window when the object is 5 m off the ground at .5 seconds;

g = 10 m/s/s, and

t = .5sec

$5=\frac{1}{2}(-10)(.5)^2$ +h and

5 = -5(.5)² + h and

5 = -5(.25) + h and

5 = -1.25 + h so

h = 6.25

That's how high the window is above the ground.

8 0

2 years ago

For what absolute value of the phase angle does a source deliver 71 % of the maximum possible power to an RLC circuit

kherson [118]

Answer: the absolute value of the phase angle is 28°

Explanation:

taking a look at expression for the instantaneous electric power in an AC circuit;

P = VI -------let this be equation 1

p is power, v is voltage and I is current;

for maximum power

P_max = V_rms × I_rms --------let this be equ 2

where P_max is the maximum power, V_rms is the rms value of voltage and I_rms is the rms value of current.

Also for average electric power in an AC circuit

P_avg = V_rms × I_rms × cos²∅ -------let this be equ 3

where P_avg is the average power and cos∅ is the power factor

now from equation 2; P_max = V_rms × I_rms

so p_max replaces V_rms × I_rms in equation 3

we now have

P_avg = P_max × cos²∅

so we substitute

expression for the given value of the average power is

P_avg = P_max × 75%

p_avg = P_max.78/100

for the expression of the average electricity in an AC circuit

P_max.78/100 = P_max × cos²∅

78/100 = cos²∅

to get the absolute value of phase angle

∅ = cos⁻¹ ( √(78/100))

∅ = cos⁻¹ ( 0.8832)

∅ = 27.969 ≈ 28°

Therefore the absolute value of the phase angle is 28°

8 0

2 years ago

How much power does it take to lift 30.0 N 10.0 m high in 5.00 s?

Rudik [331]

Power = work/time = (Force times distance)/time

= (30N *10.0m)/5.00s = 300/5 = 60 Watts

7 0

3 years ago

Read 2 more answers

What is the BEST example of a purebred

ki77a [65]

no se nada pvodebrhtre

8 0

3 years ago

(a) A space vehicle is launched vertically upward from the Earth's surface with an initial speed of vi that is comparable to but

ad-work [718]

Energy Conservation Theory,

$(k+v)_i=(k+v)_f \quad \text { (No air resistone)}\\$

$\frac{1}{2} m v_i^2-\frac{G m M_\epsilon}{R_\epsilon}=0-\frac{G m M_\epsilon}{R_\epsilon+h}$

$v_{e x^2}{ }^2-v_i^2=\frac{v_{e^2 R_t} R_t}{R_t t h}\\&\frac{1}{v_{B C^2-v_1^2}^2}=\frac{R_E+h}{v_{e^2 R_E} R_E}\\\\\\h=\frac{R_E V_1^2}{v_{\text {esc }}^2-v_1^{\beta^2}}$

<h3>What is law of energy conservation?</h3>

The principle of energy conservation states that energy is neither created nor destroyed. It may change from one sort to another. Just like the mass conservation rule, the legitimacy of the preservation of energy depends on experimental perceptions; hence, it is an experimental law. The law of preservation of energy, too known as the primary law of thermodynamics

To learn more about Energy Conservation Theory, visit;

brainly.com/question/8004680

#SPJ4

7 0

1 year ago