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3 years ago

A student is on a balcony 15.6 m above the street. She throws a ball vertically downward at 10.7 m/s.

Physics

1 answer:

andrew11 [14]3 years ago

3 0

Answer:

20.65 m/s

Explanation:

You are gonna wanna use a calculator for this one

so we will write all the known variables:

h = 15.6 m

initial velocity (u) = 10.7 m/s

acceleration (a) = 10 m/s/s (gravity)

From the third equation of motion:

v² - u² = 2ah

v² - (10.7)² = 2(10)(15.5)

v² - (10.7)² = 312

v² = 312 + 114.49

v² = 426.49

v = 20.65 m/s

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When conducting objects (such as metals) are connected for a brief time, charge can be made to flow quite easily from one to the

sukhopar [10]

Answer:

a) charges of the opposite, b) Δq = q₄₂-q₄₁, force is repulsive

c) q = 5.27 10⁻⁵ C

Explanation:

a) In electrostatic studies it is found that charges of the same sign repel and charges of the opposite sign attract.

On the other hand, as the force between the spheres is attractive, the charges on them are of different sign

b) When the balls touch, the charges are quickly distributed between the two spheres, therefore there are two possibilities:

* if the charges were equal and as they are of the opposite sign, they are neutralized, therefore the spheres remain uncharged

The force between them is zero

* if the charges are different, a residual charge remains

Δq = q₄₂-q₄₁

that is distributed between the two spheres and the force between them is repulsive

c) For this case the charges on the two spheres is equal

q₄₁ = q₄₂ = q

the force is repulsive so the charges are of the same sign.

We can apply Coulomb's law

F = $k \frac{q_1q_2}{r^2}$

in this case

F = $k \frac{q^2}{r^2}$

q = $\sqrt{ \frac{F \ r^2}{k} }$

let's calculate

q = $\sqrt{ \frac{25 \ 1^2}{9 \ 10^{9}} }$ = $\sqrt{27.7778 \ 10^{-10}}$

q = 5.27 10⁻⁵ C

7 0

3 years ago

A solar water heater for domestic hot-water supply uses solar collecting panels with a collection efficiency of 40.0 % in a loca

Stells [14]

Answer:

46.19 L

Explanation:

The efficiency of the solar water heater is 40% which means 40% of the solar energy is converted to useful energy, ie. used to heat the water.

Useful energy = P = solar energy * available area * efficiency

P = 200 W/m^2 * 29.5 m^2 * 40%

P = 2360 W = 2.36 kJ/s

This means that 2.36 kJ of useful energy will be utilized per second. Converting this to the useful energy in hour gives us:

Average energy in one hour = 2.36 kJ/s * 3600 s/h = 8496 kJ

The specific heat capacity of water is 4.18 kJ/kg.C which means it will take 4.18 kJ of energy to raise the temperature of 1 kg of water by 1 degree C. Equating the energy change of the water for the given temperature rise and mass (unknown) to the useful energy utilized in one hour, we can solve to determine the unknown mass. This will give us the mass of water heated in one hour:

Energy = mass * specific heat capacity * (final temperature - initial temperature)

8496 = mass * 4.18 * (60 - 16)

mass = 46.19 kg

Lastly, this mass has to be converted to volume. Assuming density of water is constant through out the heating process:

volume = mass / density

volume = 46.19 kg / 1 kg/L

volume = 46.19 L

7 0

3 years ago

The single-pole, single-throw switch is normally wired ? between the source and the load to turn devices on and off.

zzz [600]

In series.

Single-pole and single-throw switch:

A switch with only one input and one output is referred to as a Single Pole Single Throw (SPST) switch. This indicates that it has a single output terminal and a single input terminal.

A single pole, one throw switch functions as an on/off switch in circuits. The circuit is turned on when the switch is closed. The circuit is shut off when the switch is open.

Thus, SPST switches are relatively basic in design.

Circuit for a single-pole, single-throw (SPST) switch

Types:

According to the application, it can be divided into three categories, including:

Simple SPST

(ON)-OFF, Push-to-close, SPST Momentary

ON-(OFF), Push-to-Open, SPST Momentary

Inches Switch SPST

Learn more about terminal here:

brainly.com/question/14236970

#SPJ4

7 0

2 years ago

A 30.0-kg child sits on one end of a long uniform beam having a mass of 20.0 kg, and a 40.0-kg child sits on the other end. The

qaws [65]

let the length of the beam be "L"

from the diagram

AD = length of beam = L

AC = CD = AD/2 = L/2

BC = AC - AB = (L/2) - 1.10

BD = AD - AB = L - 1.10

m = mass of beam = 20 kg

m₁ = mass of child on left end = 30 kg

m₂ = mass of child on right end = 40 kg

using equilibrium of torque about B

(m₁ g) (AB) = (mg) (BC) + (m₂ g) (BD)

30 (1.10) = (20) ((L/2) - 1.10) + (40) (L - 1.10)

L = 1.98 m

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3 years ago

what percentage of North American adults may be functioning below their potential due to prolonged exposure to stress

Yuliya22 [10]

I believe the percentage is between 15-20%. Stress is a well known factor that affects the performance of people.

6 0

3 years ago