Answer:
what is the social problem about
Explanation:
To solve this problem we will apply the concept related to the conservation of the Momentum. We will then start considering that the amount of initial momentum must be equal to the amount of final momentum. Considering that all the objects at the initial moment have the same initial velocity (Zero, since they start from rest) the final moment will be equivalent to the multiplication of the mass of each object by the velocity of each object, so
Initial Momentum = Final Momentum

Here,
= mass of Raft
= Mass of swimmers 1
= Mass of swimmers 2
= Initial velocity (of the three objects)
= Velocity of Raft
Replacing,

Solving for 


Therefore the velocity the rarft start to move is 0.3618m/s
The correct answer D: all of the above
Answer:
a) C.M 
b) 
Explanation:
The center of mass "represent the unique point in an object or system which can be used to describe the system's response to external forces and torques"
The center of mass on a two dimensional plane is defined with the following formulas:


Where M represent the sum of all the masses on the system.
And the center of mass C.M 
Part a
represent the masses.
represent the coordinates for the masses with the units on meters.
So we have everything in order to find the center of mass, if we begin with the x coordinate we have:


C.M 
Part b
For this case we have an additional mass
and we know that the resulting new center of mass it at the origin C.M
and we want to find the location for this new particle. Let the coordinates for this new particle given by (a,b)

If we solve for a we got:




And solving for b we got:

So the coordinates for this new particle are:

Answer:
4.399 Nm
Explanation:
The maximum Torque on a coil is given as,
τ = BNIA...................... Equation 1
Where τ = Maximum torque exerted on the coil, B = Magnetic Field, N = Number of turns, I = Current, A = Area.
Given: N = 45.5 Turns, B = 0.49 T, I = 26.7 mA = 0.0267 A,
A = πr², Where r = radius of the coil, r= 4.85 cm = 0.0485 m
A = 3.14(0.0485)²
A = 7.39×10⁻³ m².
Substitute into equation 1
τ = 45.5×0.49×26.7×7.39×10⁻³
τ = 4.399 Nm