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Olegator [25]
2 years ago
15

On an ice skating rink, a girl of mass 50 kg stands stationary, face to face with a boy of mass 80 kg. The children push off of

one another, and the boy moves away with a velocity of +3 m/s. What is the final velocity of the girl?
–1.9 m/s
+1.9 m/s
–4.8 m/s
+4.8 m/s
Physics
2 answers:
irakobra [83]2 years ago
6 0
Use conservation of momentum.

Initial momentum = 0

Final momentum = momentum of the girl + momentum of the boy = inifial momentum = 0.

Momentum of the girl = - momentum of the boy

mass of the girl * velocity of the girl = - mass of the boy * velocity of the boy

50 kg * velocity of the girl = - 80 kg * 3m/s

=> velocity of the girls = -80 kg * 3m/s / 50 kg = - 4.8 m/s

Answer: - 4.8 m/s
GaryK [48]2 years ago
3 0

Answer:

c. –4.8 m/s

Explanation:

:D :) :(

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A lever has a 36cm input arm and a 6cm output arm. find MA.
Nady [450]

6

Explanation:

The mechanical advantage is a factor that measures how input force increases using a machine.

A lever is a simple machine with the fulcrum at the center.

To calculate the mechanical advantage M.A of levers we use the expression below;

M. A = \frac{F_{b} }{F_{a} } = \frac{a}{b}

F_{a} = input force

F_{b} = output force

a is the distance of the input force from the fulcrum

b is the distance of the output force from the fulcrum

Given

a = 36cm

b = 6cm

M.A = \frac{36cm}{6cm} = 6

learn more:

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6 0
2 years ago
The electric field 1.5 cm from a very small charged object points toward the object with a magnitude of 180,000 N/C. What is the
Ray Of Light [21]

Answer:

q = 4.5 nC

Explanation:

given,

electric field of small charged object, E = 180000 N/C

distance between them, r = 1.5 cm = 0.015 m

using equation of electric field

E = \dfrac{kq}{r^2}

k = 9 x 10⁹ N.m²/C²

q is the charge of the object

q= \dfrac{Er^2}{k}

now,

q= \dfrac{180000\times 0.015^2}{9\times 10^9}

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the charge on the object is equal to 4.5 nC

8 0
2 years ago
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A nonuniform, 80.0-g, meterstick balances when the support is placed at the 51.0-cm mark. At what location on the meterstick sho
Gnoma [55]

Answer:34 cm

Explanation:

Given

mass of meter stick m=80 gm

stick is balanced when support is placed at 51 cm mark

Let us take 5 gm tack is placed at x cm on meter stick so that balancing occurs at x=50 cm mark

balancing torque

80\times 10^{-3}(51-50)=5\times 10^{-3}(50-x)

80=5(50-x)

80=250-5x

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x=\frac{170}{5}

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2 years ago
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Anton [14]

Answer:

Option B, 93 cm

Explanation:

An diagram of the seed's motion is attached to this solution.

This is very close to a projectile motion question. And the quantity to be calculated, how far along the grant a seed released would travel is called the Range.

And this would be obtained from the equations of motion,

First of, the height of the plant is related to some quantities of the motion with this relation.

H = u(y) t + 0.5g(t^2)

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(substituting the t = √(2H/g) derived from above

R = u(x) √(2H/g)

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R = 4.6 √(2×0.2/9.8) = 0.929 m = 0.93 m = 93 cm. Option B.

QED!

6 0
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Answer:

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A team of astrophysicists led by Michael Kramer, conducted a study on how these gravitational waves will impact the time in which the radio waves emitted by pulsars will reach Earth. The result of the study proved the theory of General Relativity to be accurate up to 99.95%.

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