Suppose a small metal object, initially at a temperature of 60 degrees, is immersed in a room which is held at the constant temperature of 90 degrees. It takes 3 minutes for the temperature of the object to reach 75 degrees. Calculate the heat transfer coefficient
r
, i. e. the constant of proportionality in the differential equation that describes Newton's law of cooling.

initial speed when it is dropped is 150 ft/s

now at the same moment the acceleration due to gravity is perpendicular to its velocity

so as we know that

now we have centripetal acceleration a = 32 ft/s^2 as its perpendicular to velocity

while tangential acceleration at the same moment will be zero

so

now radius of curvature is given as

so the radius of curvature just after it is dropped is 703.125 ft

it is b. absorbs thermal energy