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3 years ago

What does it mean when work is positive?

Physics

1 answer:

Degger [83]3 years ago

7 0

Answer:

To have a positive job, the two vectors must have the same direction

Explanation:

Work is a scalar defined as the scalar product of two vectors, the froce and the displacement. To have a positive job, the two vectors must have

collinear and that their arrows point in the same direction.

You can also appreciate this from the work equation

W = F. r

bold indicate vector

W = F r cos θ

With θ the angle between force and displacement

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The strength of the gravitational attraction depends on the mass of the objects involved and on the distance between them. The g

wlad13 [49]

Answer:

The gravitational force between two objects depends only on their masses.

i think sorry if its wrong!!

Explanation:

3 0

3 years ago

Read 2 more answers

A parachuter, falling with a constant speed, drops 456m in 14.4s.

monitta

Answer:

The parachuter is falling at a speed of 31.667 meters per second.

Explanation:

Given that parachuter falls at constant speed and travelled distance and time are known, the unknown is speed, measured in meters per second, which is obtained by the following kinematic expression:

$s = \frac{d}{t}$

Where:

$d$ - Travelled distance, measured in meters.

$t$ - Time, measured in seconds.

If $d = 456\,m$ and $t = 14.4\,s$ , the speed of the parachuter is:

$s = \frac{456\,m}{14.4\,s}$

$s = 31.667\,\frac{m}{s}$

The parachuter is falling at a speed of 31.667 meters per second.

3 0

3 years ago

Which one has more thermal energy?

Digiron [165]

Answer:

a bathtub full of warm water

Explanation:

Even though the water in a filled bathtub may be at the same temperature as water in a teacup, the water in the bathtub has more thermal energy because it contains a greater number of water molecules.

8 0

3 years ago

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You are standing on a train station platform as a train goes by close to you. As the train approaches, you hear the whistle soun

adoni [48]

Answer: v = (33320 - 340f2)/( f2 + 98)

Explanation: this question refers to Doppler effect, hence,

f1 = { V / (V - v)} x f2

f1 = 98Hz, f2 = 76 Hz, V = 340m/s, v = ?, fs = fsourcs

For f1,

98 = { 340 / (340 + v)} x fs ...(i)

for f2,

f2 = { 340 / (340 - v)} x fs ... (ii)

Divide (ii) by (i)

98/f2 = [{ 340 / (340 + v)} x fs]÷ [ 340 / (340 - v)} x fs]

98/f2 = {340 / (340 + v)} x fs x (340 - v)} / 340 x fs

98/f2 = (340 + v)/ (340 - v)

Cross multiplying

98(340 - v) = f2 (340 + v)

33320 - 98v = 340f2 + vf2

Collecting like terms

vf2 +98v = 33320 - 340f2

v(f2 +98) = 33320 - 340f2

v = (33320 - 340f2)/( f2 + 98)

5 0

4 years ago

ccording to the law of inertia, if you see an object in motion slowing down, what can you conclude? a. That there must be some e

ivanzaharov [21]

Answer:

Explanation:

Newton's First law (aka law of inertia) says that any object, not subject to an external influence, must be keep in its present motion status (at rest or moving at constant speed along a straight line) forever.

So, if we see an object in motion slowing down, there must be an external infuence acting on it, that makes it slow down, like a friction force, for instance.

7 0

3 years ago