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3 years ago

R: Law of Conservation of Energy Pre-Write

Physics

1 answer:

Bad White [126]3 years ago

3 0

Answer:

V at C is 3.6 m/s

Explanation:

At A kinetic energy is zero and potential energy=mgh=0.5*9.81*0.6=2.943 J

By conservation of energy.

KE+PE=Constant

At C PE=0.6 J

the KE=2.943-0.6=2.343 J

KE=0.5*m*v^2

v=√[KE/(0.5*m)]=3.06 m/s

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Merry-go-rounds are a common ride in park playgrounds. The ride is a horizontal disk that rotates about a vertical axis at their

goldfiish [28.3K]

Answer:

2.55348650884 m/s

2.67400481907 m/s²

10.6960192763 m/s²

Explanation:

d = Diameter of the ride = 16 ft= $16\times 0.3048=4.8768\ m$

r = Radius = $\dfrac{4.8768}{2}=2.4384\ m$

t = Time taken = 6 seconds

Velocity is given by

$v=\dfrac{2\pi r}{t}\\\Rightarrow v=\dfrac{2\pi 2.4384}{6}\\\Rightarrow v=2.55348650884\ m/s$

The speed is 2.55348650884 m/s

Acceleration is given by

$a=\dfrac{v^2}{r}\\\Rightarrow a=\dfrac{(\dfrac{2\pi 2.4384}{6})^2}{2.4384}\\\Rightarrow a=2.67400481907\ m/s^2$

The acceleration is 2.67400481907 m/s²

When the speed is halved

$v=\dfrac{2\pi 2.4384}{\dfrac{6}{2}}=5.10697301768\ m/s$

$a=\dfrac{v^2}{r}\\\Rightarrow a=\dfrac{(\dfrac{2\pi 2.4384}{\dfrac{6}{2}})^2}{2.4384}\\\Rightarrow a=10.6960192763\ m/s^2$

The acceleration is 10.6960192763 m/s²

3 0

3 years ago

Your bedroom has a rectangular shape, and you want to measure its area. You use a tape that is precise to 0.001 and find that th

Anarel [89]

Answer:

(a) $17.0 m^{2}$

(b) $31.4 m^{2}$

Explanation:

(a)

The result obtained by multiplying two values which are having different precision has to express in the precision of the least precise number. So among the given values 4.79 is the least precise value; hence round off the result to 3 significant figures. For a rectangular room, area is a product of length and width, here, l is length and b is width/breadth

$Area=lb=4.79*3.547=16.9901\approx 17.0 m^{2}$

(b)

Following the same rules mentioned in part a of the question

For circular shaped bedroom, area $A={\pi (d/2)^{2}}$

$A=\pi\times (6.32/2)^{2}=31.37 m^{2}\approx 31.4 m^{2}$

The diameter of the circular room is 6.32, this is the least precise value used to calculate the area, so round off the final result to 3 significant figures

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3 years ago

11. Determine the average speed of a snail traveling 10 cm in 20 seconds.<br> I

Rudiy27

Im pretty sure the average speed is I really dont know

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3 years ago

A centrifuge rotor rotating at 9700 rpm is shut off and is eventually brought uniformly to rest by a frictional torque of 1.96 m

Mice21 [21]

We start from the definition of Torque,

$T = I \alpha$