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2 years ago

14

A 25kg child sits on one end of a 2m see saw. How far from the pivot point should a rock of 50kg be placed on the other side of

the see saw in order to perfectly balance the child and rock?

1 answer:

ivann1987 [24]2 years ago

6 0

Answer:

a rock of 50kg should be placed =drock=0.5m from the pivot point of see saw

Explanation:

τchild=τrock

Use the equation for torque in this equation.

(F)child(d)child)=(F)rock(d)rock)

The force of each object will be equal to the force of gravity.

(m)childg(d)child)=(m)rockg(d)rock)

Gravity can be canceled from each side of the equation. for simplicity.

(m)child(d)child)=(m)rock(d)rock)

Now we can use the mass of the rock and the mass of the child. The total length of the seesaw is two meters, and the child sits at one end. The child's distance from the center of the seesaw will be one meter.

(25kg)(1m)=(50kg)drock

Solve for the distance between the rock and the center of the seesaw.

drock=25kg⋅m50kg

drock=0.5m

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vesna_86 [32]

Answer:

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2 years ago

A fisherman casts his bait toward the river at an angle of 25° above the horizontal. As the line unravels, he notices that the b

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Answer:

$v_{o}=18m/s$

Explanation:

According to the exercise we know the angle which the bait was released and its maximum height

$\beta =25\\y=2.9m$

To find the initial y-component of velocity we need to do the following steps:

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$v_{oy}=\sqrt{2(9.8m/s^{2} )(2.9m)} =7.53m/s$

Since the bait is released at 25º

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1 year ago

it possible that the net kinetic energy for two objects be zero while the net momentum is zero? Explain.

svp [43]

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2 years ago

An all female guitar septet is getting ready to go on stage. The lead guitarist, Kira,who is always in tune, plucks her low E st

matrenka [14]

Answer:

Buffy > Aiko > Chandra > Freja > Evita

Explanation:

Beats occur when two waves of nearby frequencies overlap. The number of beats per second is equal to the difference in the frequency.

Let

$f=$ Frequency of Kira

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The beat frequency of Kira and Aiko is therefore,

$f_{beat}=|f_2-f_1|$

Substituting $f$ for $f_2$ and $3Hz$ for $f_{beat}$ , we get

$3Hz=|f-f_1|\\f_1=f+3Hz$

From the above equation, we see that beats increase

when

$f_2 =$ Frequency of Chandra

The beat frequency of Kira and Chandra is therefore,

$1Hz=|f-f_2|\\f_2=f-1Hz$

From the above equation, we see that beats decrease

When

$f_3=$ Frequency of Evita

The beat frequency of Kira and Evita is therefore,

$5Hz=|f-f_3|\\f_3=f-5Hz$

From the above equation, we see that beats decrease

When

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The beat frequency of Kira and Freja is therefore,

$3Hz=|f-f_4|\\f_4=f-3Hz$

From the equation above, we see that beats decrease

When

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The beat frequency of Kira and Buffy becomes,

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From the equation above, we see that beats increase

Hence, the rank of members based on initial frequencies from largest to smallest is Buffy > Aiko > Chandra > Freja > Evita

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1 year ago

The electric field at a point 2.8 cm from a small object points toward the object with a strength of 180,000 N/C. What is the ob

givi [52]

Answer:

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Explanation:

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Electric field at a point is given by :

$E=\dfrac{kQ}{r^2}$

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2 years ago