Answer:
D. 0.9
Explanation:
Calculating minimum coefficient of static friction, we first resolve the forces (normal and frictional) acting on the vehicle at an angle to the horizontal into their x and y components. After this, we can now substitute the values of x and y components into equation of static friction. Diagrammatic illustration is attached.
Resolving into x component:
∑
------(1)
Resolving into y component:
∑
------(2)
Static frictional force,
μ
------(3)
substituting
from equation (1) and
from equation (2) into equation (3)
μ
μ
μ 
μ 
The angle the vehicles make with the horizontal α = 42°
μ ≥ tan 42°
μ ≥ 0.9
(NH4)2CO3(s) ⇄ 2NH3(g) + CO2(g) + H2O (g)
The effect that adding water (H2O) have in reaction above is that The concentration of the product would decrease, and the concentration of reactant would increase. (answer C)
<u><em>Explanation</em></u>
- If the concentration of one substance is changed, the equilibrium shift to minimize the effect of that change.
- H2O in reaction above is a product.
- Increase of water (H2O) concentration will led to the shift of equilibrium to the left ( reactant side) .The concentration of reactant increase as that of product decrease.
The correct answer is option D
The Ohm's Law states that current passing through a conductor is directly proportional to the voltage across the conductor.
Current =voltage/ resistance
The resistance causes hindrance in the path of the current and does not allows it to flow so, we must reduce the resistance to increase the flow of current in the conducting wire.
Answer:

Explanation:
- We have to make a hollow sphere of inner radius
and outer radius
.
Then the mass of the material required to make such a sphere would be calculated as:
Total volume of the spherical shell:

And the volume of the hollow space in the sphere:

Therefore the net volume of material required to make the sphere:


- Now let the density of the of the material be
.
<u>Then the mass of the material used is:</u>


Answer: 22.5 km
Explanation: Solution:
v=d/t
Derive to find d
d= vt
= 45 km/h x 0.5 h
= 22.5 km
Cancel hours and the remaining unit is in km.