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3 years ago

A car traveling at 23m/s starts to decelerate steadily. It comes to a complete stop in 7 seconds. What is the acceleration?

1 answer:

7 0

The car has an initial velocity $v_0$ of 23 m/s and a final velocity $v$ of 0 m/s. Recall that for constant acceleration,

$v=v_0+at$

The car stops in 7 s, so the acceleration is

$0\,\dfrac{\mathrm m}{\mathrm s}=23\,\dfrac{\mathrm m}{\mathrm s}+a(7\,\mathrm s)$

$\implies a\approx-3.29\,\dfrac{\mathrm m}{\mathrm s^2}$

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cylindrical container is to be constructed to be open at the top with a volume of 27π cubic meters using the least amount of mat

Llana [10]

Answer:

radius comes out to be 3 m

height of the cylinder comes out to be 3m

Explanation:

given

volume of cylinder = 27π m³

π r² h = 27π

r² h = 27.............(1)

surface area of cylinder open at the top

S = 2πrh + π r²

$S = 2\pi \dfrac{27}{r} + \pi r^2$

$\frac{\mathrm{d} s}{\mathrm{d} r}=\frac{\mathrm{d}}{\mathrm{d} r} (2\pi \dfrac{27}{r} + \pi r^2)$

$\frac{\mathrm{d} s}{\mathrm{d} r}=54\pi \dfrac{-1}{r^2}+2\pi r$

$\frac{\mathrm{d} s}{\mathrm{d} r}=0$

for least amount of material requirement.

$\dfrac{54\pi }{r^2} = 2\pi r\\r=3m$

hence radius comes out to be 3 m

for height put the value in the equation 1

so, height of the cylinder comes out to be 3m

3 0

3 years ago

Read 2 more answers

Consider a household that uses 14,000 kWh of electricity and 900 gal of fuel oil, per year, during a heating season. The average

MissTica

Answer:

reduction in the amount of CO₂ emissions by that household per year is 9517.2 lbm per year

Explanation:

given data

electricity consume = 14000 kWh

fuel consume = 900 gal

CO₂ produced of fuel = 26.4 lbm/gal

CO₂ produced of electricity = 1.54 lbm/kWh

oil and electricity usage = 21 percent

to find out

the reduction in the amount of CO₂ emissions

solution

we calculate the amount of CO₂ produce here that is

amount of CO₂ produce = ( electricity consume×CO₂ produce electricity + fuel consume × CO₂ consume fuel ) ........................1

put here value

amount of CO₂ produce = ( 14000 × 1.54 + 900 × 26.4 )

amount of CO₂ produce = 45320 lbm/yr

we know reduction is 21%

reduction in amount of CO₂ produced is

reduction in CO₂ produced = 45320 × 21%

reduction in CO₂ produced = 9517.2 lbm per year

so reduction in the amount of CO₂ emissions by that household per year is 9517.2 lbm per year

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3 years ago

The light bulb converts electrical energy into light and _________.

KATRIN_1 [288]

Heat is the answer but I need to use 20 characters to post :)

5 0

3 years ago

Aluminum and copper are good ____ because they don't have a strong hold on valence electrons. * a. Insulators b. Transistors c.

SOVA2 [1]

aluminum and copper are C.) conductors

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3 years ago

1. Give an example of how rock can be weathered.

Alenkasestr [34]

Answer:

Explanation:

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3 years ago