physics

a body is acted on by forces F1=16N,180°,F2= 50 N ,040°,F3=28,150°,calculate the magnitude (correct to one decimal)and the direction(to the nearest degree)of the resultant of the three forces

Differential equations: Newton's Law of Cooling

Need help on this one. DE Newton's Law of Cooling

At 9 A.M., a thermometer reading 70°F is taken outdoors where the temperature is
l 5°F. At 9: 05 A.M., the thermometer reading is 45°F. At 9: 10 A.M., the thermometer is
taken back indoors where the temperature is fixed at 70°F. Find (a) the reading at
9: 20 A.M. and (b) when the reading, to the nearest degree, will show the correct
(70°F) indoor temperature.