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ivanzaharov [21]

3 years ago

8

Why is net force a vector sum A.All forces have direction and magnitude B.Forces can only be attractive C.All forces are contact

forces D.There are four fundamental forces

1 answer:

Alexus [3.1K]3 years ago

3 0

Answer:

A

Explanation:

Forces are vector quantities because they have both magnitude and direction.

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Two tugboats pull a disabled supertanker. Each tug exerts a constant force of 2.20×106 N , one at an angle 19.0 ∘ west of north,

valina [46]

Answer:

$=2.99\times10^9J$

Explanation:

According to the question

net force F = 2.20×10^6 N

displacement $S = 0.72\times10^3m$

from figure , the horizontal forces are same in magnitude and opposite direction.

so , neglect these two forces.

we can take only vertical components of the force.

total force F' = F cos 19° + F cos 19°

= 2×F×cos 19° ................. (1

therefore , total work is

W = F'S

= (2F cos19)×S

$= (2)(2.20\times10^6 N)cos19° (0.720\times10^3 m)$

$=2.99\times10^9J$

6 0

3 years ago

Communications satellites are placed in orbits so that they always remain above the same point of the earth's surface.A Part com

masya89 [10]

Answer:

24 hours

$7\times 10^{-5}\ rad/s$

Explanation:

If a satellite is in sync with Earth then the period of each satellite is 24 hours.

$T=24\times 60\times 60\ s$

Angular velocity is given by

$\omega=\dfrac{2\pi}{T}\\\Rightarrow \omega=\dfrac{2\pi}{24\times 60\times 60}\\\Rightarrow \omega=7\times 10^{-5}\ rad/s$

The angular velocity of the satellite is $7\times 10^{-5}\ rad/s$

3 0

3 years ago

What’s contact force ?

kodGreya [7K]

Explanation:

Contact force is any force that requires contact. An object that exerts a force on another object by touching it is exerting a contact force. Examples of contact force are friction and normal force.

Examples of a non-contact force are gravity and magnetism.

5 0

3 years ago

Read 2 more answers

You are conducting an experiment inside a train car that may move along level rail tracks. A load is hung from the ceiling on a

katrin2010 [14]

Answer:

b

c

e

h

Explanation:

Note that the swing direction was not giving in the question and direction could be sideways (in a turn) or in a track or both

The question show something in common ...acceleration

So let's look at the statements and pick the correct ones

a is false while b is correct as the train is accelerating

c is correct. The train is accelerating even thou the speed could not be ascertained

d is false and not feasible as the train is accelerating

e is true as the train maybe moving at a constant speed in a circle

f is false. This could be constant velocity in a circle. Same as g (false)

h is true. It's accelerating

7 0

3 years ago

The diagram shows waves of sound travelling through the air. By which factor is the sound intensity decreased at 3 meters?

SIZIF [17.4K]

The diagram is missing; however, we know that the intensity of a sound wave is inversely proportional to the square of the distance from the source:
$I(r)= \frac{1}{r^2}$
where I is the intensity and r is the distance from the source.

We can assume for instance that the initial distance from the source is r=1 m, so that we put
$I= \frac{1}{r^2}= \frac{1}{(1)^2}=1$
The intensity at r=3 m will be
$I= \frac{1}{r^2}= \frac{1}{(3)^2}= \frac{1}{9}$
Therefore, the sound intensity has decreased by a factor $1/9$ .

8 0

3 years ago

Read 2 more answers