Review Conceptual Example 11 before starting to solve this problem. The number of unstable nuclei remaining after a time t = 4.20 yr is N, and the number present initially is N0. Find the ratio N/N0 for each of the following.

(a) 14C6 (half-life = 5730 yr; Enter your answer to at least 4 significant figures.
(b) 15O8 (half-life = 122.2 s; use t = 1.00 h, since otherwise the answer is out of the range of your calculator)
(c) 3H1 (half-life = 12.33 yr).

c because the news are a source of information of things that happen on the daily and shows evidence about that particular topic

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s

the best answer for these questions would be:

1.            c. is smaller

2.            d) concrete operational

3.            b) interaction with the environment – the children interact with their environment can them learn more.

4.            a) parents who reason openly with children can limit a child’s cognitive ability.

according to jean piaget, in what stage of cognitive development are children able to understand conservation task?

b. preoperational

just took it