Answer:Explained Below
Explanation:
Tycho Brahe saw a super nova which inspired him to study astronomy.His observations are 5 times more accurate than other astronomers of his time and thus he was given a private island to study about astronomy .He made most accurate naked eye measurements ever.
So he can be said to be the "greatest naked eye astronomer of all time"
Answer:

Explanation:
given,
width of door dimension = 1 m
mass of door = 15 Kg
mass of bullet = 10 g = 0.001 Kg
speed of bullet = 400 m/s


a) from conservation of angular momentum





Answer:
Because china was in war, and her parents didn't have enough money for to go to school.
Answer:
43.7 °C
Explanation:
= Coefficient of linear expansion of brass = 
= Coefficient of linear expansion of steel = 
= Initial length of brass = 31 cm
= Initial length of steel = 11 m
= Total change in length = 3 mm
Total change in length would be


The final temperature is 43.7 °C