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3 years ago

15 POINTS!!

Physics

1 answer:

sleet_krkn [62]3 years ago

8 0

Hello !

<u>Quelle affirmation est correcte à propos de la substance inconnue? </u>

<u />

<u>Son point de fusion est de 17 ° C. </u>

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A worker is thinking about two ways to get a box up 1.2 m onto a loading dock. He can use a force of 250 N to lift it straight u

harina [27]

Answer:

<em>The second option has a lower power output. P=30 W</em>

Explanation:

<u>Mechanical Power </u>

It is a physical magnitude that measures the rate a work W is done over time t.

$\displaystyle P=\frac{W}{t}$

Since W=F.d

$\displaystyle P=\frac{F.d}{t}$

The first option means the worker will lift the box by a distance of 1.2 meters in 3 seconds by applying 250 N of force. That produces a power of

$\displaystyle P=\frac{(250). (1.2)}{3}=100\ Watt$

The second option requires the worker applies 75 N of force and travel a distance of 4 meters for 10 seconds, thus the power is

$\displaystyle P=\frac{(75). (4)}{10}=30\ Watt$

The second option has a lower power output

7 0

4 years ago

A bullet with an initial kinetic energy of 400 J strikes a wooden block where a 8000 N resistive force stops the bullet. What is

Sindrei [870]

Answer:

d = 0.05 [m] = 50 [mm]

Explanation:

We must remember the principle of conservation of energy which tells us that energy is transformed from one way to another. For this case, the initial kinetic energy is transformed into useful work that is equal to the product of force by distance.

$E_{k}=F*d\\400 = 8000*d\\d = 0.05 [m] = 50 [mm]$

5 0

3 years ago

A car of mass 750 kg accelerates away from traffic lights. At the end of the first 100 m it has reached a speed

malfutka [58]

the work done on the car by the force of its engine is 78,000 J.

" The work done on the car by the force of friction is 24,000 J.

Increasing the car's kinetic energy at the end of the first 100 m is 54,000J

a. Completed work = force x distance. Engine output = 780 N, that is,

780 N x 100 m = 78,000 J.

b. Completed work = force x distance. Friction force = 240 N, that is,

240 N x 100 m = 24,000 J.

c. Kinetic energy = 1 \ 2 x m x v2

= 1 \ 2 x 750 kg x 12 squared = 375 x 144 = 54,000 J.

<h3>How powerful is the engine of a car? </h3>

Mainstream car and truck engines typically produce 100-400 pounds. -Torque feet. This torque is generated by the engine piston as it moves up and down on the engine crankshaft, causing the engine to rotate (or twist) continuously.

Learn more about work done here: brainly.com/question/25573309

#SPJ10

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2 years ago

Why are light-years more convenient than miles, kilometers, or astronomical units (au) for measuring the distances to stars and

Tomtit [17]

Answer:

sEE BELOW

Explanation:

Well.....because the numbers are 'astronomical'....meaning VERY, VERY , VERY LARGE

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2 years ago

Is it a good thing for people to live on Mars?

SSSSS [86.1K]

No. it is not good for people to live on Mars.

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3 years ago

Read 2 more answers