In the textbook the kind of idealized object that described in section on radiation laws that it absorbs all the radiation falling for it because it is not giving off any radiation on its own. And about the black sweater worn by one of your classmates it goes the same.
Answer:
B. Directional speed........
Answer:
Using
Period ( P) is given as
P~√(L/g).
a) since mass has no effect on the period of a pendulum. So, the period will remain 1.8seconds
b) using the formula above ,period varies with the square root of the length. Thus , when the length doubles, the period is multiplied by √2. So, the period is 1.8s*√2 = 2.54s
c) in this case, the period is multiplied by √(1/2).
1.8√(1/2)=1.27s.
d) amplitude of the pendulum doesn't affect the period (unless itsvery high, so, the period is still 1.8s
