Need some help with question 20

l = 420 cm

Step-by-step explanation:

20.

Central angle  = 60°

The radius of circle, r = 7 cm

We need to find the length of the arc. We can find it as follows :

So, the length of the arc is equal to 420 cm.

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)

it shoild be o

step-by-step explanation: