Answer: B or "diamonds are rare,valuable gems".
Explanation:
since the link does not show very much, I don't know if A is correct or not. D is incorrect because that is an opinion. C is incorrect.
Answer:
See explanation
Explanation:
We have to convert to angular velocity in rads-1 as follows;
Angular velocity in rad/s = 2π/60 × 1900 rpm = 199 rad/s
Given that
angular velocity =angle turned /time taken
Time taken = angle turned/angular velocity
Converting 35° to radians we have;
35 × π/180 = 0.61 radians
Time taken = 0.61 radians/199 rad/s
Time taken = 0.0031 seconds
Answer:
Q = - 4312 W = - 4.312 KW
Explanation:
The rate of heat of the concrete slab can be calculated through Fourier's Law of heat conduction. The formula of the Fourier's Law of heat conduction is as follows:
Q = - kA dt/dx
Integrating from one side of the slab to other along the thickness dimension, we get:
Q = - kA(T₂ - T₁)/L
Q = kA(T₁ - T₂)/t
where,
Q = Rate of Heat Loss = ?
k = thermal conductivity = 1.4 W/m.k
A = Surface Area = (11 m)(8 m) = 88 m²
T₁ = Temperature of Bottom Surface = 10°C
T₂ = Temperature of Top Surface = 17° C
t = Thickness of Slab = 0.2 m
Therefore,
Q = (1.4 W/m.k)(88 m²)(10°C - 17°C)/0.2 m
<u>Q = - 4312 W = - 4.312 KW</u>
<u>Here, negative sign shows the loss of heat.</u>
Answer:
B. x - t graph
Explanation:
A position-time (x-t) graph is a graph of the position of an object against (versus) time.
Generally, the slope of the line of a position-time (x-t) graph is typically used to determine or calculate the velocity of an object.
An instantaneous velocity can be defined as the rate of change in position of an object in motion for a short-specified interval of time. Thus, an instantaneous velocity is a quantity that can be found by measuring the slope of a line that is tangent to a point on the graph.
Hence, the x - t graph also referred to as the position-time graph is used for determining the instantaneous velocity from the slope.
<u>For example;</u>
Given that the equation of motion is S(t) = 4t² + 2t + 10. Find the instantaneous velocity at t = 5 seconds.
Solution.
Differentiating the equation, we have;
Substituting the value of "t" into the equation, we have;
S(5) = 42 m/s.
Resistance can be calculated by Ohm's law
As per ohm's law we will have

here we will have
voltage = 220 volts
current = 10 A
So by the above formula we will have


So resistance of the bulb is 22 ohm.