Answer:
Force = Mass x Acceleration
Explanation:
Friend #1 gets at least 2/5 of a pizza.
Friend #2 gets at least 2/5 .
Friend #3 gets at least 2/5 .
Friend #4 gets at least 2/5 .
Friend #5 gets at least 2/5 .
Friend #6 gets at least 2/5 .
Sum . . . . . . . . . at least 12/5 of a pizza.
Simplify . . . . . . at least 2.4 pizzas.
-- If pizzas can be bought by the half, they should order at least <em>2-1/2 pizzas.</em>
-- If only whole pizzas have to be ordered, then they should order at least <em>3 pizzas.</em>
B. By vibrations in wires or strings
A 150-g metallic rod with a specific heat of 0.11 cal/g.°C absorbs 82.5 calories of heat and its temperature increases from 20 °C to 25 °C.
<h3>What is specific heat?</h3>
It is the heat required to raise the temperature of the unit mass of a given substance by a given amount (usually one degree).
A metallic rod of mass 150 g (m) absorbs 82.5 cal of heat (Q) and its temperature raises from 20 °C to 25 °C. We can calculate the specific heat (c) of the metal using the following expression.
Q = c × m × ΔT
c = Q / m × ΔT
c = 82.5 cal / 150 g × (25 °C - 20 °C) = 0.11 cal/g.°C
A 150-g metallic rod with a specific heat of 0.11 cal/g.°C absorbs 82.5 calories of heat and its temperature increases from 20 °C to 25 °C.
Learn more about specific heat here: brainly.com/question/21406849
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When light moves from a medium with higher refractive index to a medium with lower refractive index, the critical angle is the angle above which there is no refracted light, and all the light is reflected. The value of this angle is given by
where n2 and n1 are the refractive indices of the second and first medium, respectively.
In the first part of the problem, light moves from glass to air (
) and the critical angle is
. This means that we can find the refractive index of glass by re-arranging the previous formula:
Now the glass is put into water, whose refractive index is
. If light moves from glass to water, the new critical angle will be