The answer is:
d.It’s a composite because it’s a mixture of cement, sand, and other granular pieces.
The explanation:
Concrete is a composite, since it is composed of various elements like sand, gravel & water.
Aggregate consists of large chunks of material in a concrete mix, generally a coarse gravel or crushed rocks such as limestone, or granite, along with finer materials such as sand. Cement, most commonly Portland cement, is associated with the general term "concrete.
To solve this problem we will apply the relation of Ohm's law, at the same time we will use the concept of resistance in a cable, resistivity and potential difference.
According to Ohm's law we have to
Here,
V = Voltage
I = Current
R = Resistance
At the same time resistance can be described as
Here,
= Resistivity of the material
l = Length of the specimen
A = Cross-sectional area
From the above expression we can write the current as,
Replacing we have that,
Therefore the current in the wire is 3.809A
<em>Note: The value obtained for the resistivity of Tungsten was theoretically obtained and can be consulted online.</em>
Answer:
(A) -2940 J
(B) 392 J
(C) 212.33 N
Explanation:
mass of bear (m) = 25 kg
height of the pole (h) = 12 m
speed (v) = 5.6 m/s
acceleration due to gravity (g) = 9.8 m/s
(A) change in gravitational potential energy (ΔU) = mg(height at the bottom- height at the top)
height at the bottom = 0
= 25 x 9.8 x (0-12) = -2940 J
(B) kinetic energy of the Bear (KE) =
= = 392 J
(C) average frictional force =
- change in KE (ΔKE) = initial KE - final KE
- ΔKE = -
- when the Bear reaches the bottom of the pole, the final velocity (Vf) is 0, therefore the change in kinetic energy becomes ΔKE = - 0 = 392 J
\frac{-(ΔKE+ΔU)}{h}[/tex] =
= = 212.33 N
The answer for number 8. Is B.
Answer:
i guess the body is not accelerating