Why was Earth very hot at the beginning of its formation? Select all that apply. Heat came from Earth being continuously struck by other small bodies.
Heat came from nuclear fusion happening in the core of Earth.
Heat came from radiation that was produced by nearby stars.
Heat came from the supernova that led to the formation of the solar system.

heat came from the supernova that led to the formation of solar system

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west