Romeo (85.0 kg) entertains juliet (47.0 kg) by playing his guitar from the rear of their boat at rest in still water, 2.70 m away from juliet, who is in the front of the boat. after the serenade, juliet carefully moves to the rear of the boat (away from shore) to plant a kiss on romeo's cheek. how far does the 83.0-kg boat move toward the shore it is facing?

Δ = 0.59 m towards shore

Explanation:

Given:

m r = 85.0 kg , m j = 47.0 kg , m b = 83.0 kg , L = 2.70 m

X'cm = X cm

mj xj + mb xb + mr xr / mj + mb +mr

L (mb / 2 +mr) = mj (L/2 - Δ + L/2) + mb ( L/2 - Δ) + mr ( L/2 - Δ + L/2)

Δ (mj + mb +mr) = L (mj +mb/2 + mr) - L (mb/2 +mr)

Δ = L * mj / (mj +mb + mr)

Replacing numeric

Δ = 2.70 m * [ 47.0 kg / ( 47.0 + 83.0 + 85.0 )]

Δ = 0.59 m towards shore

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation:

the answer is 12 as i may remember

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