Answer:
D) D = 
, E) (C, D) = ( 
Explanation:
Part D) two expressions are indicated
3C + 4D = 5
2C +5 D = 2
let's simplify each expression
3C + 4D = 5
4D = 5 - 3C
we divide by 4
D =
The other expression
2C +5 D = 2
2C = 2 - 5D
C = 
we can see that the correct result is 1
Part E.
It is asked to solve the problem by the substitution method, we already have
D =
we substitute in the other equation
2C +5 D = 2
2C +5 (5/4 - ¾ C) = 2
we solve
C (2 - 15/4) + 25/4 = 2
-7 / 4 C = 2 - 25/4
-7 / 4 C = -17/4
7C = 17
C = 
now we calculate D
D = 
D = 5/4 - 51/28
D =
D = - 16/28
D = 
the result is (C, D) = ( )
Answer:
Metals
Explanation:
The group of elements with few valence electrons that conducts heat and electricity is known metals. Metals are good conductors of heat and electricity. The outer electrons in metals are loosely bound to the atom and are thus able to freely move around and conduct electricity and heat.
Explanation:
By Hooke's Law,
F=kx
The only force acting here is weight, and x is the extension of the string (you need to convert this to mm) so
mg=kx
(0.15)(9.81)=k ((420-300)x10^-3)
Then just solve this equation.
Answer:
35.3 N
Explanation:
U = 0, V = 0.61 m/s, s = 0.39 m
Let a be the acceleration.
Use third equation of motion
V^2 = u^2 + 2 as
0.61 × 0.61 = 0 + 2 × a × 0.39
a = 0.477 m/s^2
Force = mass × acceleration
F = 74 × 0.477 = 35.3 N
Answer:
B. Convection
D. Conduction
Explanation:
Conduction and convection are the two most prominent processes that helps transfer energy outward to the earth's crust.
- Energy within the core is a function of the radioactive decay and frictional heating.
- Also, heat that accreted during the formation of the earth is a significant source of internal energy.
- The heat is conducted away by the process of convection. This is possible due to temperature differences between different parts of the earth
- Conduction is made made possible due to the metallic bodies in the core and other part of the inner earth.
