Answer: a) 0.78 m/s b) 1.57 m/s
Explanation:
M = father's mass
m = son's mass = M/3
V = father's initial speed
v = son's initial speed
(1/2)MV^2 = (1/2)*(1/2)*m v^2
M*V^2 = (1/2)(M/3)v^2
V^2/v^2 = 1/4
V = v/2
Second equation:
(1/2)M*(V + 1.4)^2 = (1/2)m*v^2
= (1/2)*(M/3)*(3V)^2
cancel out the M's and (1/2)'s
(V + 1.4)^2 = 3V^2
V^2 + 2.8V + 1.96 = 3V^2
V^2 -1.4V -0.98 = 0
V^2 = 0.98/0.4 = 2.45
V = 1.57
The short answer to how the aurora happens is that energetic electrically charged particles (mostly electrons) accelerate along the magnetic field lines into the upper atmosphere, where they collide with gas atoms, causing the atoms to give off light.
Answer:
The second dart leaves the gun two times as faster than the first one.
Explanation:
Assuming no energy loss during the spring-dart energy transfer, we have by the conservation of energy principle
Given an arbitrary 
and its double, 
, launch velocities are
Have a universal record base. Everyone is able to understand the data compiled since the same measurement systems are being used around the world. This is just to simplify all of the information.
