Answer:
per mole of pentane = 3157.53 kJ/mol
Explanation:
Given:
Mass of pentane, m = 0.468 gram
Molar mass of pentane, M = 72.15
Now, mol of pentane, n = mass/M = 0.468/72.15 = 0.00648 mol of C5H12
Now,
ΔT = 23.65 - 20.45 = 3.2°C
Heat capacity of the calorimeter, C = 2.21 kJ/°C
Specific heat capacity of the water, Cp = 4.184 J/g.°C
Now,
the heat gained = the heat lost

also,


or

and
Now,

we have,
(Here negative sign depicts the release of the heat)
per mole of pentane =-20460.8/(0.00648 ) = 3157.53 kJ/mol
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
Answer:
4/10 of L.
Explanation:
A stopped pipe is a pipe with one closed end and one opened end. it is also called a closed pipe.
The fundamental mode of a stopped pipe is also called its fundamental frequency, and is f₁=v/4L.
Where f₁=fundamental frequency, v= velocity of sound, L= Length of pipe.
The fifth harmonic of the stopped pipe f₅ =5v/4L .................(1)
For an open pipe,
Fundamental mode is also called fundamental frequency f₁₀=v/2l₀ .......... (2)
Where f₁₀ = fundamental frequency of a closed pipe, v= velocity of sound and l₀=length of the resulting open pipe.
from the question, the fundamental mode of the resulting open pipe = The fifth harmonic of the original stopped pipe.
∴ f₅=f₁₀
⇒5v/4L = v/2l₀
Equating v from both side of the equation,
⇒ 5/4L = 1/2l₀
Cross multiplying the equation,
5×2l₀ = 4L× 1
10l₀ = 4L
Dividing both side of the equation by the coefficient of l₀ i.e 10
10l₀/10 = 4L/10
∴ l₀ = 4/10(L)
∴ 4/10 of L must be cut off
Answer:
<em>You would use the kinematic formula:</em>

Explanation:
The upwards vertical motion is ruled by the equation:

Where:





Naming Δy = y - y₀, the equation becomes:

Then, you just need to substitute with Δy = 0.1m, t = 2s, and g = 9.8m/s², ans solve for the intital vertical velocity.
The light bulb, it takes electrical energy and turns it into l<span>ight energy!</span>