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2 years ago

A car takes 9 m to stop after the driver applies the brakes.

1 answer:

4 0

Depends upon how soon you want to stop. You know the mass of the car, you know the initial velocity of 8.9 m/s. You know the final velocity which is zero. You can now calculate the deceleration of the car if you know how soon you want to stop.

Let's say you want to stop in one second.

a = (vf - vi) / t = - 8.9 m/s^2 (negative sign indicates deceleration).

F = ma = 800 x 8.9 = 7120 Newtons (kg*m/s^2)

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How can acceleration be changed without changing speed?

katrin [286]

Since velocity is a speed and a direction, there are only two ways for you to accelerate: change your speed or change your direction—or change both. If you're not changing your speed and you're not changing your direction, then you simply cannot be accelerating—no matter how fast you're going.

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3 years ago

A 34.0 %-efficient electric power plant produces 800 MW of electric power and discharges waste heat into 20∘C ocean water. Suppo

mojhsa [17]

Answer:

77647

Explanation:

$\eta$ = Efficiency = 34%

Power used in 1 home = 0.02 MW

Total power is

$P=\dfrac{800}{\eta}\\\Rightarrow P=\dfrac{800}{0.34}\\\Rightarrow P=2352.94117\ MW$

Waste of power

$2352.94117-800=1552.94117\ W$

Number of homes would be given by

$n=\dfrac{1552.94117}{0.02}=77647.0585\ homes$

The number of homes that could be heated with the waste heat of this one power plant is 77647

8 0

3 years ago

If 20 beats are produced within a single second, which of the following frequencies could possibly be held by two sound waves tr

zhuklara [117]

The correct choice is

D. 22 Hz and 42 Hz.

In fact, the beat frequency is given by the difference between the frequencies of the two waves:

$f_B = |f_1 -f_2|$

In this problem, the beat frequency is $f_B=20 Hz$ , therefore the only pair of frequencies that gives a difference equal to 20 Hz is

D. 22 Hz and 42 Hz.

4 0

3 years ago

Read 2 more answers

How does the color of water affect its evaporation rate

olga_2 [115]

Well my thinking is that the lighter the slower the water evaporates or the darker the faster becuase dark colors absorb light and allows a lot of heat to be generated or not at all.

8 0

3 years ago

Which energy conversion takes place when a solar cell is used to light a street lamp?

allsm [11]

Answer:

the answer is for the question is B

8 0

3 years ago