Answer:
Explanation:
deceleration a
v² = u² - 2as
0 = 7.5² - 2 a x .15
a = 187.5 m / s²
If R be the force exerted by hand
R- mg = ma
R = mg + ma
= .27 ( 9.8 + 187.5 )
= 53.27 N
Work done by hand
= force x displacement
= 53.27 x - .15
= - 8 J
Answer:
D) Roger is incorrect. Only a chemical change is taking place as evidenced by the light and heat of the burning candles.
Explanation:
- A physical change is a change in which there is no formation of new substances. Examples of physical changes are the melting or the evaporation of a substance (all phase transitions are examples of physical changes): in such cases, there is no formation of new substances.
- A chemical change is a change in which new substances form. Examples of chemical changes are the chemical reactions: for instance, when a candle burns, a reaction is taken place (oxygen is burnt, transforming into carbon dioxide + heat + light, so this is an example of chemical change).
Therefore, the correct answer is
D) Roger is incorrect. Only a chemical change is taking place as evidenced by the light and heat of the burning candles.
Answer:
<em>The total surface area of the seven little spheres is 1.91 times the total surface area of the bigger sphere.</em>
Explanation:
<u>Volume of a Sphere</u>
The volume of a sphere of radius r is given by:
The volume of each little sphere is:
When the seven little spheres coalesce, they form a single bigger sphere of volume:
Knowing the volume, we can find the radius rb by solving the formula for r:
Multiplying by 3:
Dividing by 4π:
Taking the cubic root:
Substituting:
The surface area of the seven little spheres is:
The surface area of the bigger sphere is:
The ratio between them is:
The total surface area of the seven little spheres is 1.91 times the total surface area of the bigger sphere.
Answer:
Increase
Explanation:
If we assume the gas is ideal, then we can use the ideal gas law:
PV = nRT
If V is held constant while P increases, then T will also increase.
Answer:
yes
Explanation:
The hypothesis is scientific because there is no solid evidence to draw out the theory. Therefore the idea of other intelligence on other planets is scientific until found unworthy or scientifically proven wrong enough. Hope this helps a little:)