Which question cannot be answered through making measurements?

What is the total amount of energy stored in a 12-V, 75 A*h car battery when it is fully charged?

erma4kov [3.2K]

Explanation:

Power is current times voltage. Power is also energy per time.

P = IV = E/t

Solving for energy:

E = V It

E = (12 V) (75 Ah) (3600 s / h)

E = 3,240,000 J

E = 3240 kJ

8 0

4 years ago

A brick is thrown upward from the top of a building at an angle of 10° to the horizontal and with an initial speed of 16 m/s. If

Basile [38]

Answer:

38.47 m

Explanation:

To find the height of the building, we will use the following equation

$y_f=y_i+v_{iy}t+\frac{1}{2}at^2$

Where yf is the final height, yi is the initial height, viy is the initial vertical velocity, t is the time, and a is the acceleration due to gravity.

If the brick is in flight for 3.1 s, we can say that when t = 3.1s, yf = 0 m. So, replacing

viy = (16 m/s)sin(10) = 2.78 m/s

a = -9.8 m/s²

we get

$0=y_i+2.78(3.1)+\frac{1}{2}(-9.8)(3.1)^2$

Solving for yi

$\begin{gathered} 0=y_i-38.48 \\ y_i=38.48\text{ m} \end{gathered}$

Therefore, the height of the building is 38.48 m

6 0

1 year ago

Planets orbit the Sun, while the Moon and other satellites orbit the Earth. Such orbital motion is the result of _______ and eac

Lorico [155]

Gravity ? that is possibly the answer

8 0

4 years ago

un motor electric efectueaza un lucru mecanic de 864 j in 0.5 min.tensiunea la bornele sale este de 12v si este parcurs de un cu

GrogVix [38]

Answer:

96%

Explanation:

To find the values of the motor efficiency you use the following formula:

$E=\frac{P_o}{P_i}100$

P_o: output power = 864J/0.5min=864J/30s=28.8W

P_i: input power = I*V = (3A)(12V) = 36W

By replacing this values you obtain:

$E=\frac{28.8W}{30W}*100=96\%$

hence, the motor efficiency is about 96%

traslation:

Pentru a găsi valorile eficienței motorului, utilizați următoarea formulă:

P_o: putere de ieșire = 864J / 0.5min = 864J / 30s = 28.8W

P_i: putere de intrare = I * V = (3A) (12V) = 36W

Înlocuind aceste valori obțineți:

prin urmare, eficiența motorului este de aproximativ 96%

3 0

3 years ago

12) A neutral atom has two, eight, eight electrons in its first, second, and third energy levels.This information ________.

pentagon [3]

Answer:

C.

Explanation:

Option C

The information given in the question tells us about the number of electrons in an atom and also the number of shells in the atom. So, we will come to know about the atomic number, size and chemical properties of the atom. But we cannot determine atomic mass. Atomic mass is a function of number of neutrons and protons.

3 0

3 years ago