The kinetic energy of an object is equal to one half Its mass multiplied by its

Calculate the true mass (in vacuum) of a piece of aluminum whose apparent mass is 4.5000 kg when weighed in air. The density of

sasho [114]

Answer:

m = 4.5021 kg

Explanation:

given,

Apparent mass of aluminium = 4.5 kg

density of air = 1.29 kg/m³

density of aluminium = 2.7 x 10⁷ kg/m³

true mass of the aluminium = ?

Weight in Vacuum

W = m g

W = ρV g

Air buoyancy acting on aluminium

B = ρ₀V g

Volume is the same in both cases since the volume of the aluminum

displaces an equal amount of volume air.

Apparent weight:

ρV g − ρ₀V g = 4.5 g

ρV − ρ₀V = 4.5

$V = \dfrac{4.5}{\rho - \rho_0}$

m = ρV

$m = \dfrac{4.5\times \rho}{\rho - \rho_0}$

$m = \dfrac{4.5\times 2700}{2700 - 1.29}$

m = 4.5021 kg

4 0

3 years ago

The internal energy of a system changes because the system gains 160 J of heat and performs 309 J of work. In returning to its i

o-na [289]

Answer:

w=255

Explanation:

The change in internal energy is given by the first law:

ΔE = Q - w

where ΔE is the change in internal energy of the system

q is the heat added to the system

w is the work done *by* the system on the surroundings

So, for the first phase of this process:

ΔE = Q - w

Q=160J

w=309J

ΔE = 160J - 309J = -149J

To bring the system back to its initial state after this, the internal energy must change by +149J (the system myst gain back the 149 J of energy it lost). We are told that the system loses 106 J of heat in returning to its initial state, so the work involved is given by:

ΔE = Q - w

+149J = -106J - w

255J = -w

w = -255J

5 0

3 years ago

A solution is known as a homogeneous mixture because _[blank]_.

alekssr [168]

Answer:

The solute fully dissolves in the solvent

Explanation:

This is because for a solution to be called a homogeneous mixture, all the solute must be dissolved in the solvent, without the particles of the solute being visible in the solvent.

8 0

3 years ago

A coil consists of 180 turns of wire. Each turn is a square of side d=30 cm, and a uniform magnetic field directed perpendicular

alexira [117]

Answer:

Emf induced i equal to 329.4 volt

Explanation:

Note : Here i think we have to find emf induced in the coil

Number of turns in the coil N= 180

Sides of square d = 30 cm = 0.3 m

So area of the square $A=0.3\times 0.3=0.09m^2$