According to Newton's Law of Heating, the Temperature $T$ Of a Cold Object Increases at a Rate Proportional to a Cold

According to Newton's Law of Heating, the temperature $T$ of a cold object increases at a rate proportional to the difference between $T$ and the temperature $T _ { o }$ of its surroundings.(a) Write down this law as a differential equation.(b) Assume the room temperature is 70 $^\circ$ F. If it takes 10 minutes for a can of soda to warm up from 30 $^\circ$ F to 35 $^\circ$ F, and how long it takes to warm up a can of soda from 30 $^\circ$ F to 40 $^\circ$ F.