A0.70-kg block is hung from and stretches a spring that is attached to the ceiling. a second block is attached to the fi rst one, and the amount that the spring stretches from its unstrained length triples. what is the mass of the second block?

1.4 kg

Explanation:

m1 = 0.7 kg

Let the mass of second block is m.

x1 = x

x2 = 3x

According to the Hooke's law

F1 = - kx1

m1 g = - k x

0.7 g = - k x (1)

When both the blocks are placed

(m1 + m2) g = - k x2

(0.7 + m) g = - 3 k x   (2)

Divide equation (2) by equation (1), we get

(0.7 + m) / 0.7 = 3

0.7 + m = 2.1

m = 2.1 - 0.7

m = 1.4 kg

thus, the mass of second block is 1.4 kg.

connect the batteries in series and hope

this could be newton#'s law of cooling. the cooling curve is exponential