Air caught in the ball of foil makes the ball less dense than water
The correct answer is D. I alread took this test.
A.) reference group
"A reference group includes individuals or groups that influence our opinions, beliefs, attitudes and behaviors. They often serve as our role models and inspiration"(study.com).
Acceleration will be 9.81 if it goes downwards. If it accelerates upwards it will be -9.81m/s^2
Answer:
r = 1.61 x 10^{11} m
Explanation:
energy radiated (H) = 2.7 x 10^31 W
surface temperature (T) = 11,000 k
assuming ε = 1 and taking σ = 5.67 x 10^{-8} W/m^{2}.K^{4}
we can find the radius of the star from the equation below
H = A x ε x σ x T^{4}
where area (A) = 4 x π x r^{2} (assuming it is a sphere)
therefore the equation becomes
H = 4 x π x r^{2} x ε x σ x T^{4}
2.7 x 10^31 = 4 x π x r^{2} x 1 x 5.67 x 10^{-8} x (11,000)^{4}
r = 
r = 1.61 x 10^{11} m