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3 years ago

A force acting on an object does no work if

2 answers:

8 0

If the force is not in the direction of the object’s motion then a <span> force acting on an object does no work
work is done if force is applied on a body and body covers some distance in the direction of the force
W=FS
hope it helps</span>

KIM [24]3 years ago

3 0

Answer: the force is not in the direction of the object’s motion.

Explanation:

Work = Force. Displacement

⇒ W = F. s = F s cos θ

Thus, work is said to be done when a force displaces an object from its position in the direction of the force.

If the force is less the frictional force, the object would not move. An object accelerates when a force is applied. Sometimes, the direction of force and direction of motion is not same. In that case, no work is said to be done.

For example, when porter lifts the weight on head and moves forward. The weight is perpendicular to the direction of motion. cos 90° = 0 ⇒ W = 0

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A satellite of mass M = 270kg is in circular orbit around the Earth at an altitude equal to the earth's mean radius (6370 km). A

zubka84 [21]

To solve this problem we will apply the concepts related to Orbital Speed as a function of the universal gravitational constant, the mass of the planet and the orbital distance of the satellite. From finding the velocity it will be possible to calculate the period of the body and finally the gravitational force acting on the satellite.

PART A)

$V_{orbital} = \sqrt{\frac{GM_E}{R}}$

Here,

M = Mass of Earth

R = Distance from center to the satellite

Replacing with our values we have,

$V_{orbital} = \sqrt{\frac{(6.67*10^{-11})(5.972*10^{24})}{(6370*10^3)+(6370*10^3)}}$

$V_{orbital} = 5591.62m/s$

$V_{orbital} = 5.591*10^3m/s$

PART B) The period of satellite is given as,

$T = 2\pi \sqrt{\frac{r^3}{Gm_E}}$

$T = \frac{2\pi r}{V_{orbital}}$

$T = \frac{2\pi (2*6370*10^3)}{5.591*10^3}$

$T = 238.61min$

PART C) The gravitational force on the satellite is given by,

$F = ma$

$F = \frac{1}{4} mg$

$F = \frac{270*9.8}{4}$

$F = 661.5N$

5 0

3 years ago

Find the orbital speed v for a satellite in a circular orbit of radius R.Express the orbital speed in terms of G, M, and R.

AlekseyPX

<h2>Answer: $V=\sqrt{G\frac{M}{R}}$ </h2>

The velocity of a satellite describing a circular orbit is <u>constant</u> and defined by the following expression:

$V=\sqrt{G\frac{M}{R}}$ (1)

Where:

$G$ is the gravity constant

$M$ the mass of the massive body around which the satellite is orbiting

$R$ the radius of the orbit (measured from the center of the planet to the satellite).

Note this orbital speed, as well as orbital period, does not depend on the mass of the satellite. I<u>t depends on the mass of the massive body.</u>

In addition, this orbital speed is constant because at all times <u>both the kinetic energy and the potential remain constant</u> in a circular (closed) orbit.

5 0

3 years ago

Why aren’t the Appalachian Mountains still as tall as the Himalayas?

stealth61 [152]

Answer:

mountains are limited in their theoretical height by several processes. First is isostasy: the bigger a mountain gets, the more it weighs down its tectonic plate, so it sinks lower. ... Bottom line: mountains can get taller than Mount Everest in earth gravity, like the Appalachians probably did—but not much taller.

3 0

2 years ago

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A ball is thrown straight up into the air and passes a window 3 seconds after being released. It passes the same window on its w

melomori [17]

The initial velocity of the ball is 55.125 m/s.

<h3>Initial velocity of the ball</h3>

The initial velocity of the ball is calculated as follows;

During upward motion

h = vi - ¹/₂gt²

h = vi - 0.5(9.8)(3²)

h = vi - 44.1 ----------------- (1)

During downward motion

h = vi + ¹/₂gt²

h = 0 + 0.5(9.8)(1.5)²

h = 11.025 ----------- (2)

solve (1) and (2) together, to determine the initial velocity of the ball

11.025 = vi - 44.1

vi = 11.025 + 44.1

vi = 55.125 m/s

Thus, the initial velocity of the ball is 55.125 m/s.

Learn more about initial velocity here: brainly.com/question/19365526

#SPJ1

8 0

1 year ago

Can a person run at a speed of 20 meters per second

tensa zangetsu [6.8K]

Answer:

Explanation:

The fastest recorded time for a person to run 100 metres is 9.58 seconds, which is the equivalent of 10.4 metres per second

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2 years ago

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