A camper stands in a valley between two parallel cliff walls. He claps his hands and notices that the echo from the nearby wall returns 0.9 s later while the echo from the farther wall returns 1.10 s later. If the air temperature is -10 C, how wide is the valley?

1/0.14nm = 10^10/1.4 a lot

which piece of furniture will have the most inertia and give the furniture movers the most difficulty in moving?  

answer

a 75kg dining table

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.