Answer:
because of carbon content in wood harms environment , although forest can be replenished but no one wanted to plant a tree in his/ her home. And also, cutting of woods causes environmental imbalances. Further, burning of wood causes a lot of pollution. Hence, it is advisable not to use wood as a fuel.
Explanation:
Answer:
Formula: Remove the zero from the speed, multiply the figure by itself and then multiply by 0.4. The figure 0.4 is taken from the fact that the braking distance from 10 km/h in dry road conditions is approximately 0.4 metres.
Answer:
The average atomic mass of element X is 17.561 u.
Explanation:
Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.
Formula used to calculate average atomic mass follows:
.....(1)
We are given:
Mass of isotope X-17 = 17 u
Percentage abundance of isotope X-17 = 65.20 %
Fractional abundance of isotope 1 = 0.6520
Mass of isotope X-18 = 18 u
Percentage abundance of isotope X-18 = 13.50 %
Fractional abundance of isotope X-18 = 0.1350
Mass of isotope X-19 = 19 u
Percentage abundance of isotope X-19 =21.30%
Fractional abundance of isotope X-19 = 0.2130
Putting values in equation 1, we get:
![\text{Average atomic mass of Z}=\sum[(17 u\times0.6520 )+(18 u\times 0.1350)+(19 u\times 0.2130)]](https://tex.z-dn.net/?f=%5Ctext%7BAverage%20atomic%20mass%20of%20Z%7D%3D%5Csum%5B%2817%20u%5Ctimes0.6520%20%29%2B%2818%20u%5Ctimes%200.1350%29%2B%2819%20u%5Ctimes%200.2130%29%5D)

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Answer:
The 1470 kJ of energy supplied by the yogurt would be consumed by 150 W of work (efficiency of 20%) in about 32.7 h. Then if people is not careful, easily would have more energy from the food that the amount that can consume exercising.
Explanation:
Step 1.
- Energy supplied: 1470 kJ = 1470000 J.
- Rate of energy used for the : 150 W = 150 J/s. <em>This means that each second of this kind of work requieres 150 J of energy,</em>
Step 2
For this case, efficiency is defined as the relationship between the actual rate of energy used, to the rate of energy consumed to obtain it. So:

Then the rate of energy required for this work, is calculated solving for
:

<em>This means that for a work that as a rate of 150 J/s , It requieres to consume energy at a rate of 750 J/s.</em>
Step 3
Now, it is possible to calculate how much time would be needed to consume the 1470000 J of energy of the yogurt. It done using this relationship:

Where Energy stands for the total amount of energy that would be consumed, and rate stans for the rate of energy consumption, Then the time would be:

Then if for the consumption of 1470 kJ of energy is required almost 33 hours, Then is easy to see that the amount of enegy that can be obtain of food would much more than the amount that can be depleted by exercise