I would choose B. exosphere. Astronomers study outer space, planets and ect.
I this is tricky one sec.. I would go with b
Change in color
Change in color is a physical reaction
Answer:
I think -7 N. Netforce is 3N-10N= -7N
Explanation:
To find this we should use the equation Ek=1/2mv^2 where Ek is the kinetic energy, m is the mass and v is the velocity. So by this Ek=1/2*1*30^2 which then makes Ek=450 joules
