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2 years ago

If the girl skater has a mass of 30 kg and moves backward at 5 m/s, what is the velocity or the boy skater

1 answer:

3 0

Question: Two people stand facing each other at a roller-skating rink then push off each other. If the girl skater has a mass of 30 kg and moves backward at 5 m/s, what is the velocity of the boy skater if his mass is 50 kg?

Answer:

3 m/s

Explanation:

Applying,

The Law of conservation of momentum

Momentum of the girl skater = momentum of the boy skater

MV = mv...................... Equation 1

Where M = mass of the girl skater, V = velocity of the girl skater, m = mass of the boy skater, v = velocity of the boy skater

From the question, we were asked to calculate v

v = MV/m.................. Equation 1

Given: M = 30 kg, V = 5 m/s, m = 50 kg

Substitute these values into equation 1

v = (30×5)/50

v = 3 m/s

Hence the velocity of the the boy skater is 3m/s

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Suppose the ring rotates once every 4.30 ss . If a rider's mass is 58.0 kgkg , with how much force does the ring push on her at

Stells [14]

Answer:

422.36 N

Explanation:

given,

time of rotation = 4.30 s

T = 4.30 s

Assuming the diameter of the ring equal to 16 m

radius, R = 8 m

$v = \dfrac{2\pi R}{T}$

$v = \dfrac{2\pi\times 8}{4.30}$

v = 11.69 m/s

now, Force does the ring push on her at the top

$- N - m g = \dfrac{-mv^2}{R}$

$N + m g = \dfrac{mv^2}{R}$

$N = \dfrac{mv^2}{R}- m g$

$N = m(\dfrac{v^2}{R}- g)$

$N = 58\times (\dfrac{11.69^2}{8}- 9.8)$

N = 422.36 N

The force exerted by the ring to push her is equal to 422.36 N.

6 0

3 years ago

Calculate the current flowing if a charge of 36 kilocoulombs flows in 1 hour.

o-na [289]

Answer:

Current = 10 Amperes.

Explanation:

Given the following dat;

Quantity of charge, Q = 36 kilocoulombs (KC) = 36 * 1000 = 36000C

Time = 1 hour to seconds = 60*60 = 3600 seconds

To find the current;

Quantity of charge = current * time

Substituting in the equation

36000 = current * 3600

Current = 36000/3600

Current = 10 Amperes.

6 0

2 years ago

What's the difference between meteoroids, meteorites, and meteors?

SVEN [57.7K]

You're talking about a grain of sand or a stone or a rock that's drifting in space, and then the Earth happens to get in the way, so the stone falls down to Earth, and it makes a bright streak of light while it's falling through the atmosphere and burning up from the friction.

-- While it's drifting in space, it's a meteoroid.

-- While it's falling through the atmosphere burning up and making a bright streak of light, it's a meteor.

-- If it doesn't completely burn up and there's some of it left to fall on the ground, then the leftover piece on the ground is a meteorite.

4 0

3 years ago

Can anybody tell me the right answer ? please and thank you !!

ad-work [718]

Answer:

c. selenium

Explanation:

sulfur and selenium are in the same group

3 0

3 years ago

(a) In what direction would the ship in Exercise 3.57 have to travel in order to have a velocity straight north relative to the

shtirl [24]

Answer:

Direction of ship: 9.45° West of North

Ship's relative speed: 7.87m/s

Explanation:

A. Direction of ship: since horizontal of the velocity of boat relative to the ground is 0

Vx=0

Therefore, -VsSin∅+VcCos∅40°

Sin∅ = Vc/Vs × Cos 40°

Sin∅ = 1.5/7 ×Cos40°

Sin∅= 0.164

∅= Sin-¹ (0.164)

∅= 9.45° W of N

B. Ship's relative speed:

Vy= VsCos∅ + Vcsin40°

= 7Cos9.45° + 1.5sin40°

= 7×0.986 + 1.5×0.642

= 7.865

= 7.87m/s

4 0

3 years ago