A raindrop initially has mass M_0 = 0.277~\mathrm{g}M 0 =0.277 g and, due to gravity, starts falling from rest through a cloud. One way to model the growth of a raindrop is to assume that its mass grows proportionally to the product of its instantaneous mass and velocity, according to the following equation \dfrac{dM}{dt} = kMV. dt dM =kMV. Here, kk is a constant of proportionality, which we take to be k = 6.99~\mathrm{m}^{-1}.k=6.99 m −1 . What is the speed of the rain drop when its mass has doubled its initial value?

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.

moisture is lackin, and organic acids are scarce.

chemical energy --> gravitational potential energy --> kinetic energy --> elastic potential energy --> gravitational potential energy

explanation:

when emma starts the hike, the chemical energy stored in her body is used to climb up the mountain, and so she gains gravitational potential energy (because at the end, she will be at a higher height h above the ground). then she goes bungee jumping: as she falls, this gravitational potential energy is converted into kinetic energy (because her speed increases as she falls down), until the point when the rope stretches, and she stops moving. at that moment, all the kinetic energy is converted into elastic potential energy due to the stretching of the rope. then, this energy is released because the rope returns to its natural length, and emma gains a small increase in altitude , so she gains some gravitational potential energy.