Depending on the model, all-electric vehicles can go about ______

(a) For a given material, would you expect the surface energy to be greater than, the same as, or less than the grain boundary e

aksik [14]

Answer:

(a) Surface energy is greater than grain boundary energy due to the fact that the bonds of the atoms on the surface are lower than those of the atoms at the grain boundary. The energy is also directly proportional to the number of bonds created.

(b) The energy of a high-angle grain boundary is higher than that of a small-angle grain boundary because the high-angle grain boundary has a higher misalignment and smaller number of bonds than a small-angle grain boundary.

Explanation:

(a) Surface energy is greater than grain boundary energy due to the fact that the bonds of the atoms on the surface are lower than those of the atoms at the grain boundary. The energy is also directly proportional to the number of bonds created.

(b) The energy of a high-angle grain boundary is higher than that of a small-angle grain boundary because the high-angle grain boundary has a higher misalignment and smaller number of bonds than a small-angle grain boundary.

5 0

2 years ago

A composite wall is to be used to insulate a freezer chamber at -350C. Two insulating materials are to be used with conductiviti

choli [55]

Answer:

thickness1=1.4m

thickness2=2.2m

convection coefficient=0.33W/m^2K

Explanation:

you must use this equation to calculate the thickness:

L=K(T2-T1)/Q

L=thickness

T=temperature

Q=heat

L1=0.04*(0--350)/10=1.4m

L2=0.1(220-0)/10=2.2m

Then use this equation to calculate the convective coefficient

H=Q/(T2-T1)

H=10/(250-220)=0.33W/m^2K

7 0

3 years ago

2. A

Charra [1.4K]

Answer: Projectile

Explanation:
A projectile is any object that once projected or dropped continues in motion by its own inertia and is influenced only by the downward force of gravity.

8 0

3 years ago

A long, horizontal, pressurized hot water pipe of 15cm diameter passes through a room where the air temperature is 24degree C. T

solmaris [256]

Answer:

Rate of heat transfer to the room air per meter of pipe length equals 521.99 W/m

Explanation:

Since it is given that the radiation losses from the pipe are negligible thus the only mode of heat transfer will be by convection.

We know that heat transfer by convection is given by

$\dot{Q}=hA(T-T_{\infty })$

where,

h = heat transfer coefficient = 10.45 $W/m^{2}K$ (free convection in air)

A = Surface Area of the pipe

Applying the given values in the above formula we get

$\dot{Q}=10.45\times \pi DL\times (130+273-(24+273))\\\\\frac{\dot{Q}}{L}=10.45\times 0.15\times \pi \times (130-24)\\\\\frac{\dot{Q}}{L}=521.99W/m$

5 0

2 years ago

When was Lamborghini's Made<br> A.) 2004<br> B.) 1963<br> C.) 1923<br> D.) 1990

Serjik [45]

Answer:

1963

Explanation:

Sant'Agata Bolognese is a small comune in the Metropolitan City of Bologna, Emilia-Romagna, in the north of Italy. It is notable for being the headquarters of the luxury automobile manufacturer Automobili Lamborghini. It is named after Saint Agatha of Sicily.

7 0

2 years ago

Depending on the model, all-electric vehicles can go about _______ miles on a single charge.