3 physics question - please help do not understand - Please ASAP?

Question

please help answer any of the 3 quesitons thank you

1. A 2.38 kg mass with an initial velocity of
v
1 = aˆı, where a = 3.67 m/s collides with
and sticks to a 2.89 kg mass with an initial
velocity of v1 = bˆj, where b = −4.8 m/s.
Find the final speed of the composite mass.
Answer in units of m/s.

2. Three point mass particles are located in a
plane:
4.25 kg located at the origin,
7.2675 kg at [(6.24 cm), (12.48 cm)],
and 3.02175 kg at [(18.6576 cm), (0 cm)].
How far is the center of mass of the three
particles from the origin? Answer in units of
cm.

3. A(n) 17 kg ob ject, initially at rest in free
space, “explodes” into three segments. The
masses of two of these segments are both 6 kg
and their velocities are 6.3 m/s. The an-
gle between the direction of motion of these
segments is 46 degrees.
What is the speed of the third segment?
Answer in units of m/s.


PLEASE SHOW WORK SO I CAN LEARN IT

THANK YOU

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Answer 1

in the i direction
2.38*3.67=(2.38+2.89)*vi

1.66 m/s
in the j direction
2.89*(-4.8)=(2.38+2.89)*vj
-2.63 m/s

The resultant speed is
sqrt(1.66^2+2.63^2)
3.11 m/s

2)
(4.25*0+7.2675*
sqrt(6.24^2+12.48^2)+
3.02175*18.6576)/
(4.25*0+7.2675+3.02175)


15.33 cm

3)
2*6*6.3*cos(46)=5*v
solve for v
v=10.5 m/s




j