Answer / Explanation:
To properly answer this question, let us define what a grain boundary is:
A grain boundary is the interface between multiple grains or crystals in a poly-crystalline material. They could also be refereed to as defects in the crystal structure and tend to decrease the electrical and thermal conductivity of structures.
Now, if we refer back to the question asked,
(a) The surface energy is grater than the grain boundary energy because surface atom have fewer bonds than atom along a grain boundary.
Consequentially, the lower the number of bonds formed, the higher the energy
(b) A higher angle grain boundary has higher misalignment and hence greater disruption of bonds (lesser number of bonds) than a small angle grain boundary. Therefore, a high angle grain boundary has higher energy.
Answer:
K = .3941 × 10³ W/m.K
Explanation:
Qcond = K A ΔT÷ L
∴K = Qcond ×L ÷ A ΔT
J ÷ S = P
P = I × V =Qcond
∴Qcond = I × V
= 0.6 A × 110 V
=66 W
L = 0.12 m
ΔT = 8 °C
Qcond =33 V
Area = (πD²) ÷ 4
= [π (4 × 10⁻² )²] ÷ 4
= 1.256 × 10⁻³ m²
∴A = 1.256 × 10 ⁻³³ m²
So K = ( Qcond × L ) ÷ A ΔT
= (33) (0.12 ) ÷ (1.256 ×10⁻³ ) × 8
= 0.3941 × 10³ W/m .K
Answer:
The free body diagram of John is shown in the attached figure (in the FBD john's mass is supposed to be concentrated at his center of mass and FBD is made of center of mass)
b) As shown in the FBD the ground reaction forces are:
i) In X direction 
ii) In Y direction 
c) The respective accelerations in x and y direction's is calculated by newton's second law as indicated under
False) high intake of alcohol and sugar increases the triglycerides.
Answer:
As a science fair project, you want to launch an 950g model rocket straight up and hit a horizontally moving target as it passes 33.0m above the launch point. The rocket engine provides a constant thrust of 20.0N . The target is approaching at a speed of 18.0m/s . At what horizontal distance between the target and the rocket should you launch?
= 43.56m
Explanation:
acceleration =
(20 - (0.95 * 9.8) )/ (0.95)
= 10.68 / 0.95
= 11.24 m/s²
we use
s = ut + (1/2) at²
Given that
s= 40
u =0
s = 0 * t + (1/2) (11.24)t²
t = √(66/1.24)
t = √5.87
t = 2.42sec
hence
Horizontal distance = 18 * 2.42
= 43.56m
