Answer:
H = 27.35 m
Explanation:
From projectile motion, we know that;
h = (v_o)²/2g
Where;
v_o = 12 m/s
g = 9.8 m/s²
Thus;
h = 12²/(2 × 9.8)
h = 144/19.6
h = 7.35 m
Now, we are told that when the man is 20 m above the pillow, he lets go of
the rope.
Thus, greatest height reached by the man above the ground is;
H = 20 + h
H = = 20 + 7.35
H = 27.35 m
Answer
Explanation:
Smoking can cause lung disease by damaging your airways and the small air sacs (alveoli) found in your lungs. Lung diseases caused by smoking include COPD, which includes emphysema and chronic bronchitis. Cigarette smoking causes most cases of lung cancer.
Answer:
The statement that best describes insulators is <u><em>"Electrons within their atoms are strongly held by the nuclei"</em></u>
Explanation:
Atoms are constituted by a nucleus with positive charge (protons and neutrons), around which negative charges (electrons) revolve.
Substances that have a huge amount of "free electrons" that can move through the material are called conductors. This is due to the low resistance to the movement of the load or electric current.
Materials that do not conduct electricity are called insulators. In this case the electrons are strongly bound to the nucleus and cannot move freely. In this way a great resistance to the flow of electric current is offered.
Finally, semiconductors are the materials that can have electrical properties of conductors or insulators.
So<u><em> the statement that best describes insulators is "Electrons within their atoms are strongly held by the nuclei"</em></u>
Answer:
A
Explanation:
Let the x represent the amount of heat generated from the fossil fuel.
88% of x = 0.88 x
0.88 x was used to convert water to steam.
heat carried by steam = 40% × 0.88 x = 0.352 x
efficiency of the heat -to- work conversion = work output / work input = 0.352 x / x = 0.352 × 100 = 35.2 % which is less than 40 %
If a car is travelling 70 m.p.h that means it is travelling 70 miles PER HOUR and since we want to know half an hour we can do
70mph divided by 2 =35m.p half hour so the car is travelling 35miles in half an hour