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2 years ago

A load of bricks is lifted to the second floor of a building. How do work and power relate to this job?

Physics

2 answers:

kow [346]2 years ago

6 0

The faster the job is done, the greater the power. Just took the quiz on e2020 got 100%

Nady [450]2 years ago

5 0

The faster the job is done, the greater the power

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Review Conceptual Example 6 as background for this problem. A car is traveling to the left, which is the negative direction. The

DiKsa [7]

Answer:

(a) 1.21 m/s² (b) 1.75 m/s²

Explanation:

The initial speed of the car, u = 17.8 m/s

Case 1.

Final speed of the car, v = 23.5 m/s

Time, t = 4.68-s

Acceleration = rate of change of velocity

$a=\dfrac{23.5 -17.8 }{4.68}\\\\a=1.21\ m/s^2$

Case 2.

Final speed of the car, v = 15.3 m/s

$a=\dfrac{23.5 -15.3}{4.68}\\\\a=1.75\ m/s^2$

Hence, this is the required solution.

3 0

2 years ago

Recall that the spring constant is inversely proportional to the number of coils in the spring, or that shorter springs equate t

ruslelena [56]

Answer:

$x_1= 0.0425m$

Explanation:

Using the tension in the spring and the force of the tension can by describe by

T = kx

, T = mg

Therefore:

$m*g = k*x$

With two springs, let, T1 be the tension in each spring, x1 be the extension of each spring. The spring constant of each spring is 2k so:

$T_1 = 2k*x_1$

$2T_1 = m*g=4k x_1$

Solve to x1

$x_1=\frac{m*g}{4k}$

$x_1=\frac{k*x}{4*k}$

$x_1=\frac{x}{4}$

$x_1 = 0.170 / 4$

$x_1= 0.0425m$

7 0

2 years ago

A small steel roulette ball rolls around the inside of a 30 cm diameter roulette wheel. It is spun at 150 rpm, but is slows to 6

liraira [26]

Solution :

Given

Diameter of the roulette ball = 30 cm

The speed ball spun at the beginning = 150 rpm

The speed of the ball during a period of 5 seconds = 60 rpm

Therefore, change of speed in 5 seconds = 150 - 60

= 90 rpm

Therefore,

90 revolutions in 1 minute

or In 1 minute the ball revolves 90 times

i.e. 1 min = 90 rev

60 sec = 90 rev

1 sec = 90/ 60 rec

5 sec = $\frac{90}{60}\times 5$

= 75 rev

Therefore, the ball made 75 revolutions during the 5 seconds.

7 0

2 years ago

Basalt is pushed into the crust by subduction. It will most likely become _____.

suter [353]

Subduction is, "<span>the sideways and downward movement of the edge of a plate of the earth's crust into the mantle beneath another plate." The basalt would most likely be swallowed up into the ground.
Hope this is what you were looking for! :)

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6 0

3 years ago

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What is the definition of the half-life of a radioactive isotope?

Illusion [34]

Answer:Half-life is the amount of time it takes for the initial mass of the isotope to decompose, by half, into other lighter atoms.

Explanation:Different radioactive isotopes have different half-lives. For example, the element technetium-99m has a half life of 6 hours. This means that is 100 kg of the element is left to decay, in 6 hours, 50kg of the mass will have changed into other elements/atoms. The half-life of uranium-238 is 4.5 billion years while that of polonium-216 is only 0.145 seconds.

5 0

2 years ago

Read 2 more answers