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3 years ago

1.How is the law of conservation of energy demonstrated by the movement of the pendulum?

1 answer:

6 0

1. Law of conservation of energy states that energy cannot be created, nor destroyed, for example, windmills take kinetic energy(movement energy) and convert it into electrical energy using gears and a generator as well as the blades.

so this supports it because the pendulum never reaches the same height twice unless you reset it so the energy is always getting less and less and not randomly getting back onto the pendulum.

2.Gravity, friction and air resistance slow it down as well

3. at the top, potential energy is the amount of energy something has relative to the amount it can disperse before stopping, for example, a book on a shelf has more potential energy than that of a book on a table, this is because when the shelf book falls it will create more energy than the table book.

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Which quantity is measured in newton seconds (Ns)?

pshichka [43]

Answer:

Impulse

Explanation:

Impulse is force times time

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3 years ago

A skydiver reaches terminal velocity. Then he opens his parachute.

schepotkina [342]

Answer:

it is 0.9999.10896

Explanation:

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3 years ago

Read 2 more answers

A photovoltaic panel of dimension 2 m × 4 m is installed on the roof of a home. The panel is irradiated with a solar flux of GS

Flura [38]

Answer:

(a) the electrical power generated for still summer day is 1013.032 W

(b)the electrical power generated for a breezy winter day is 1270.763 W

Explanation:

Given;

Area of panel = 2 m × 4 m, = 8m²

solar flux GS = 700 W/m²

absorptivity of the panel, αS = 0.83

efficiency of conversion, η = P/αSGSA = 0.553 − 0.001 K⁻¹ Tp

panel emissivity , ε = 0.90

Apply energy balance equation to determine he electrical power generated;

transferred energy + generated energy = 0

(radiation + convection) + generated energy = 0

$[\alpha_sG_s-\epsilon \alpha(T_p^4-T_s^4)]-h(T_p-T_\infty) - \eta \alpha_s G_s = 0$

$[\alpha_sG_s-\epsilon \alpha(T_p^4-T_s^4)]-h(T_p-T_\infty) - (0.553-0.001T_p)\alpha_s G_s$

(a) the electrical power generated for still summer day

$T_s = T_{\infty} = 35 ^oC = 308 \ k$

$[0.83*700-0.9*5.67*10^{-8}(T_p_1^4-308^4)]-10(T_p_1-308) - (0.553-0.001T_p_1)0.83*700 = 0\\\\3798.94-5.103*10^{-8}T_p_1^4 - 9.419T_p_1 = 0\\\\Apply \ \ iteration \ method \ to \ solve \ for \ T_p_1\\\\T_p_1 = 335.05 \ k$

$P = \eta \alpha_s G_s A = (0.553-0.001 T_p_1)\alpha_s G_s A \\\\P = (0.553-0.001 *335.05)0.83*700*8 \\\\P = 1013.032 \ W$

(b)the electrical power generated for a breezy winter day

$T_s = T_{\infty} = -15 ^oC = 258 \ k$

$[0.83*700-0.9*5.67*10^{-8}(T_p_2^4-258^4)]-10(T_p_2-258) - (0.553-0.001T_p_2)0.83*700 = 0\\\\8225.81-5.103*10^{-8}T_p_2^4 - 29.419T_p_2 = 0\\\\Apply \ \ iteration \ method \ to \ solve \ for \ T_p_2\\\\T_p_2 = 279.6 \ k$

$P = \eta \alpha_s G_s A = (0.553-0.001 T_p_2)\alpha_s G_s A \\\\P = (0.553-0.001 *279.6)0.83*700*8 \\\\P = 1270.763 \ W$

3 0

3 years ago

Two astronauts, each having a mass of 74.3 kg are connected by a 13.1 m rope of negligible mass. They are isolated in space, orb

murzikaleks [220]

Answer:

L = 5076.5 kg m² / s

Explanation:

The angular momentum of a particle is given by

L = r xp

L = r m v sin θ

the bold are vectors, where the angle is between the position vector and the velocity, in this case it is 90º therefore the sine is 1

as we have two bodies

L = 2 r m v

let's find the distance from the center of mass, let's place a reference frame on one of the masses

$x_{cm}$ = $\frac{1}{M} \sum x_{i} m_{i}$ i

x_{cm} = $\frac{1}{m+m} ( 0 + l m)$

x_{cm} = $\frac{1}{2m} lm$

x_{cm} = $\frac{1}{2}$

x_{cm} = 13.1 / 2 = 6.05 m

let's calculate

L = 2 6.05 74.3 5.65

L = 5076.5 kg m² / s

4 0

3 years ago

Read 2 more answers

A car travels due east with a speed of 52.0 km/h. Raindrops are falling at a constant speed vertically with respect to the Earth

serg [7]

Answer:

a) v = 6.43 m/s

b) v = 15.8 m/s

Explanation:

Speed of car = 56 km/h

56 km/h = 14.4 m/s

Angle rain makes on the glass to the vertical = 66°

Thus knowing that the opposite side of the angle is the distance moved by the car, and the adjacent side is the distance traveled by the rain in the same time

both of which are directly proportional to their velocities

Then

tan(66°) = 14.44m/s ÷ x

or x = 14.44/tan(66°)

Which is the vertical raindrop velocity of the relative to earth

v = 6.43 m/s vertically towards earth

For v relative to the car is we have vector sum of both velocities

v = √(14.44^2 + 6.43^2) = 15.8 m/s which is the velocity relative to car

= 15.8 m/s

6 0

3 years ago