You have just designed an artificial blood substitute and want to test some of its properties

thermodynamics. For each of the following cases, indicate whether the heat and work terms other than zero are positive or negative. Determine the change in internal energy for:

$($a$)$ Heat a $500$ mL package of artificial blood from room temperature to $37\backslash$deg C$.$

$($b$)$ Cool a $500$ mL package of artificial blood from room temperature to $-70$ C$.$