Answer:
D) 11 N
Explanation:
F = mg
In the vertical
30 = m(9.8)
m = 3.06 kg
in the horizontal
F = ma
F(unknown) - 5 = 3.06(2.0)
F(unknown) = 11.12... N
Answer:
Resultant horizontal force = 143 N
Explanation:
Since the a gle is 30° northwest, then it means the resultant force will be horizontal and as such;
Resultant horizontal force = 165 * cos 30
Resultant horizontal force = 142.89
Approximating to a whole number gives;
Resultant horizontal force = 143 N
Answer:
- The thermal efficiency is 0.4113.
Explanation:
We know that the thermal efficiency is the ratio of work done by the engine over the heat taken
Now, how much work the engine do in a cycle?
We know that the work done in a cycle must be equal to the heat taken minus the heat rejected
So, the thermal efficiency will be:
Putting the values of the problem
Answer:
Explanation:
Given
N0 = 20kg (original substance)
decay constant λ = 0.179/sec
time t = 300s
We are to find N(t)
Using the formula;
n(t) = N0e^-λt
Substitute the given values
N(t) = 20e^-(0.179)(300)
N(t) = 20e^(-53.7)
N(t) = 20(4.7885)
N(t) =143.055
To know how much of the original material that is active, we will find N(t)/N0 = 143.055/20 = 7.152
About 7 times the original material is still radioactive
