Oil explorers set off explosives to make loud sounds, then listen for the echoes from underground oil deposits. Geologists suspect that there is oil under 500-m-deep Lake Physics. It’s known that Lake Physics is carved out of a granite basin. Explorers detect a weak echo 0.94 s after exploding dynamite at the lake surface. If it’s really oil, how deep will they have to drill into the granite to reach it?

790 m

Explanation:

solution:

the echo time is calculated as:

T_echo=t_(water down)+t_(granite down)+t_(granite up)+t_(water up)

0.94=500 m/1480 m/s+d_granite/6000 m/s+d_granite/6000 m/s+500 m/1480

       =790 m

answer: the rock sample is a sedimentary rock.

explanation:

it is given that:

mass of rock sample, m = 2.7 g

volume of rock sample,

so, density of rock sample will be

since, the density of rock sample is . hence, the rock sample is a sedimentary rock, whose densities varies between .

the amount of current in the coil