Answer:
5 N
Explanation:
The bucket is moving at a constant speed of 2m/s Therefore F=ma is 0 N for this to be correct the magnitude of the force exerted by the rope must be equal to the weight of the bucket which is 5 N
D. Redefine the machine’s system boundaries.
The Law of Conservation of Energy states that energy can't be created not destroyed. Energy, however, can be changed from one form to another. The law applies to isolated systems only. By redefining and expanding the system (including all factors affecting it) , the machine's ability to do work should improve.
Answer:
θ=19.877⁰
Explanation:
Given data
Velocity Va=34.0 km/h
Velocity Va=100 km/h
To find
Angle θ
Solution
We want the bird to fly with velocity Vb=100 km/h with an angle θ relative to the ground so that the bird fly due south relative to the ground.From figure which is attached we got
Sinθ=(Va/Vb)
Sinθ=(34.0/100)
θ=Sin⁻¹(34.0/100)
θ=19.877⁰
Answer:
a) 0.0288 grams
b) ![2.6*10^{-10} J/kg](https://tex.z-dn.net/?f=2.6%2A10%5E%7B-10%7D%20J%2Fkg)
Explanation:
Given that:
A typical human body contains about 3.0 grams of Potassium per kilogram of body mass
The abundance for the three isotopes are:
Potassium-39, Potassium-40, and Potassium-41 with abundances are 93.26%, 0.012% and 6.728% respectively.
a)
Thus; a person with a mass of 80 kg will posses = 80 × 3 = 240 grams of potassium.
However, the amount of potassium that is present in such person is :
0.012% × 240 grams
= 0.012/100 × 240 grams
= 0.0288 grams
b)
the effective dose (in Sieverts) per year due to Potassium-40 in an 80- kg body is calculate as follows:
First the Dose in (Gy) = ![\frac{energy \ absorbed }{mass \ of \ the \ body}](https://tex.z-dn.net/?f=%5Cfrac%7Benergy%20%5C%20absorbed%20%7D%7Bmass%20%5C%20of%20%5C%20the%20%5C%20body%7D)
= ![\frac{1.10*10^6*1.6*10^{-14}}{80}](https://tex.z-dn.net/?f=%5Cfrac%7B1.10%2A10%5E6%2A1.6%2A10%5E%7B-14%7D%7D%7B80%7D)
= ![2.2*10^{-10} \ J/kg](https://tex.z-dn.net/?f=2.2%2A10%5E%7B-10%7D%20%5C%20J%2Fkg)
Effective dose (Sv) = RBE × Dose in Gy
Effective dose (Sv) = ![1.2 *2.2*10^{-10} \ J/kg](https://tex.z-dn.net/?f=1.2%20%20%2A2.2%2A10%5E%7B-10%7D%20%5C%20J%2Fkg)
Effective dose (Sv) = ![2.6*10^{-10} J/kg](https://tex.z-dn.net/?f=2.6%2A10%5E%7B-10%7D%20J%2Fkg)