Which of the following is the best definition of energy?

Based on Archimedes' principle, the greatest buoyant force an object can experience in water is determined by which quantity?

ValentinkaMS [17]

Answer:

B. The object's volume

Explanation:

When an object is immersed in a fluid, it experiences an upward force which is called buoyant force. The magnitude of the buoyant force is given by:

$B=\rho_f V_{disp} g$

where

$\rho_f$ is the density of the fluid in which the object is immersed

$V_{disp}$ is the volume of the fluid displaced by the object

$g$ is the acceleration due to gravity

When the object is totally immersed in the fluid, $V_{disp}$ corresponds to the volume of the object; when the object is only partially immersed, $V_{disp}$ corresponds only to the volume of the part of the object immersed.

From the formula, we see that the greatest buoyant force is experienced by the object when it is fully immersed. Moreover, we see that the buoyant force depends only on one property of the object: its volume. Therefore, the correct choice is

B. The object's volume

6 0

3 years ago

Which question should Trudy write

Tanzania [10]

A real question, one with a question mark?

6 0

3 years ago

In which part of the ear are the vibrations occurring in a gas, liquid, and solid?

UkoKoshka [18]

Answer:

eardrum is the correct answer

hope this helps ❤️

Explanation:

Sound waves enter the ear canal and cause the eardrum to vibrate. Three small bones transmit these vibrations to the cochlea. This produces electrical signals which pass through the auditory nerve to the brain, where they are interpreted as sound.

5 0

3 years ago

The "steam" above a freshly made cup of instant coffee is really water vapor droplets condensing after evaporating from the hot

KiRa [710]

Answer:

$T_{f}$ = 85.7 ° C

Explanation:

For this exercise we will use the calorimetry heat ratios, let's start with the heat lost by the evaporation of coffee, since it changes from liquid to vapor state

Q₁ = m L

Where m is the evaporated mass (m = 2.00 103-3kg) and L is 2.26 106 J / kg, where we use the latent heat of the water

Q₁ = 2.00 10⁻³ 2.26 10⁶

Q1 = 4.52 10³ J

Now the heat of coffee in the cup, which does not change state is

Q coffee = M $c_{e}$ ( $T_{f}$ - $T_{i}$ )

Since the only form of energy transfer is terminated, the heat transferred is equal to the evaporated heat

Qc = - Q₁

M ce ( $T_{f}$ - $T_{i}$ ) = - Q₁

The coffee dough left in the cup after evaporation is

M = 250 -2 = 248 g = 0.248 kg

$T_{f}$ -Ti = -Q1 / M $c_{e}$

$T_{f}$ = Ti - Q1 / M $c_{e}$

Since coffee is essentially water, let's use the specific heat of water,

$c_{e}$ = 4186 J / kg ºC

Let's calculate

$T_{f}$ = 90.0 - 4.52 103 / (0.248 4.186 103)

$T_{f}$ = 90- 4.35

$T_{f}$ = 85.65 ° C

$T_{f}$ = 85.7 ° C

5 0

3 years ago

A 100-W (watt) light bulb has resistance R=143Ω (ohms) when attached to household current, where voltage varies as V=V0sin(2πft)

Phantasy [73]

Complete Question

A 100-W (watt) light bulb has resistance R=143Ω (ohms) when attached to household current, where voltage varies as V=V0sin(2πft), where V0=110 V, f=60 Hz. The power supplied to the bulb is P=V2R J/s (joules per second) and the total energy expended over a time period [0,T] (in seconds) is $U = \int\limits^T_0 {P(t)} \, dt$