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3 years ago

An Olympic skier moving at 20.0 m/s down a 30.0o slope encounters a region of wet snow, of

Physics

1 answer:

Sonja [21]3 years ago

8 0

Answer:

Option B

Explanation:

Forces acting on the skier-

F1 $= -mg sin(30)$ down the slope

F2 $= -mg cos(30)$

F3 = friction force $= 0.74 mg cos(30)$

Net force, down the slope

$= -mg sin(30)+ 0.74 mg cos(30)\\= mg(.74 cos(30)-sin(30))\\= 0.14mg\\= 1.38m$

Acceleration $= F/m= 1.38$ m/s2

Acceleration remains constant, initial speed is 20 m/s

Speed at time t is $1.38t- 20$ m/s

Distance down the slope at time t is $0.69t^2- 20t$

When the skier stops, her speed is 0. Thus,

, $1.38t- 20= 0\\t= 20/1.38\\= 14.5$ seconds

Distance travelled in 14.5 seconds $= (0.69)(14.52- 20(14.5)= -145 m$ (negative because it is down the slope).

Option B is correct

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3 years ago

Determine the total moment of inertia of a merry-go round with 5 children sitting on it. Of the five children, four are seated a

BaLLatris [955]

Answer:

Explanation:

Given that,

We have five children.

Each of mass m =30kg

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Mass of Merry go round M= 150kg

Radius of Merry go round is r =2m

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The four child that sit at the edge are 2m from the centre of the merry go round but the one at the centre is 0m from the centre

Moment of inertia?

Moment of inertia is given as

I=Σmi•ri²

For the question, the moment of inertia is the combination of inertial of child and the merry go round

I= I(merry go round) + I(four child)+ I(last child)

The merry go round is assumed to be a solid cylinder, so it is going to have the moment of inertia of solid cylinder

Then,

I(merry go round ) =½ Mr²

Also, Four of the child has the same moment of inertia, they are 2m form the centre of the merry go round why the last child has no moment of inertia

I= I(merry go round) + I(four child) +I(last child )

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When the leveling bulb is higher than the water level, the pressure in the system is greater than atmospheric pressure.

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When the leveling bulb is higher than the water level, the pressure in the system is greater than atmospheric pressure. This statement is true.

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Atmospheric pressure, which is roughly 15 pounds per square inch at sea level, is the weight of the atmosphere pressing down on each unit area of the Earth's surface. Pascals are used to express pressure in SI units; one pascal is equivalent to one newton per square meter. Almost 100,000 pascals of atmospheric pressure are present.

To learn more about pressure please visit-
brainly.com/question/12971272
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2 years ago

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