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2 years ago

The power rating of an electric lawn mower is 2000 watts if lawnmower is used for 120 seconds how many joules of work van it do

1 answer:

4 0

1 watt = 1 joule/sec

2,000 watts = 2,000 joules/sec

   (2,000 joule/sec) x (120 sec)

      = (2,000 x 120) (joule-sec/sec)

      = 240,000 joules .

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Mention three features of the Constitution and a note about them

Dvinal [7]

Answer:

Explanation:(1) a constitution is a supreme law of the land, (2) a constitution is a framework for government; (3) a constitution is a legitimate way to grant and limit powers of government officials. Constitutional law is distinguished from statutory law.

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2 years ago

Why do objects not cool to absolute zero by emitting all their thermal energy

iren [92.7K]

Answer:

Because the object should shrink its volume to zero, which is impossible

Explanation:

Let's talk about gases for simplicity. Ideal gases are governed by the ideal gas equation:

$pV=nRT$

where

p is the gas pressure

V is the volume of the gas

n is the number of moles

R is the gas constant

T is the absolute temperature

From the formula, we see that T and V are directly proportional: therefore, in order for a gas to have an absolute temperature of zero, it must also have a volume of zero, which is impossible.

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3 years ago

Which of the following statements describes the trend in the data?

AURORKA [14]

Answer:

Explanation:

The answer is D- The number of flies decreased, then leveled off.

6 0

2 years ago

An iron block of mass 10 kg rests on a wooden plane inclined at 30° to the horizontal. It is found

Kaylis [27]

I assume the 100 N force is a pulling force directed up the incline.

The net forces on the block acting parallel and perpendicular to the incline are

∑ F[para] = 100 N - F[friction] = 0

∑ F[perp] = F[normal] - mg cos(30°) = 0

The friction in this case is the maximum static friction - the block is held at rest by static friction, and a minimum 100 N force is required to get the block to start sliding up the incline.

Then

F[friction] = 100 N

F[normal] = mg cos(30°) = (10 kg) (9.8 m/s²) cos(30°) ≈ 84.9 N

If µ is the coefficient of static friction, then

F[friction] = µ F[normal]

⇒ µ = (100 N) / (84.9 N) ≈ 1.2

5 0

2 years ago

A bicyclist starting at rest produces a constant angular acceleration of 1.30 rad/s2 for wheels that are 35.5 cm in radius.

Debora [2.8K]

Answer:

a) 0.462 m/s^2

b) 31.5 rad/s

c) 381 rad

d) 135m

Explanation:

the linear acceleration is given by:

$a=\alpha *r\\a=1.30rad/s^2*(35.5*10^{-2}m)\\a=0.462m/s^2$

the angular speed is given by:

$\omega=\frac{v}{r}\\\\\omega=\frac{11.2m/s}{35.5*10^{-2}m}\\\\\omega=31.5rad/s$

to calculate how many radians have the wheel turned we need the apply the following formula:

$\theta=\frac{1}{2}\alpha*t^2\\\\t=\frac{\omega}{\alpha}\\\\t=\frac{31.5rad/s}{1.30rad/s^2}\\\\t=24.2s\\\\\theta=\frac{1}{2}*1.30rad/s^2*(24.2s)^2\\\\\theta=381rad$

the distance is given by:

$d=\theta*r$

$d=381rad*(35.5*10^{-2}m)\\d=135m$

4 0

3 years ago