Question

SAME PROBLEM NEW QUESTION:
An object with total mass mtotal = 15.3 kg is sitting at rest when it explodes into three pieces. One piece with mass m1 = 4.9 kg moves up and to the left at an angle of θ1 = 20° above the –x axis with a speed of v1 = 25.6 m/s. A second piece with mass m2 = 5.3 kg moves down and to the right an angle of θ2 = 25° to the right of the -y axis at a speed of v2 = 23 m/s.

What is the y-component of the velocity of the third piece?
Is it the same process just substituting sin for cos?
https://www.smartphysics.com/Content/smartPhysics/Media/Images/Mechanics/13/explosion3.png

Answer 1

vector (p) = vector (p1) + vector (p2) + vector (p3) = 0
=4.9*25.6*cos 160
+5.3*23*cos -65
+5.1*v3*cosθ3
The x component is the v3*cosθ3 :D

Answer 2

May I ask how you came up with the angles, I am a bit confused.

Answer 3

http://www.mathsisfun.com/geometry/images/circle-unit-sct.gif
On a unit circle, the angle is calculated as from the Ox, counter-clockwise to the vector we need. The x component as you can see, is calculated as cosθ
So if you have θ1 = 20°, the angle we need to find is 180 - 20. θ2 = 25° like that, the angle should be 90 - 25.
When you have the angle, times it with the length of the vector. It's trigonometry :D

Answer 4

Okay that make sense You have to cal

Answer 5

http://www.mathsisfun.com/geometry/unit-circle.html

Answer 6

*calculate from the same point for both angles

Answer 7

:D