What is the average velocity of the car from t=5 seconds to t=12 seconds?

Ineed the answers for these promblems i have

Suppose a force of 60 n is required to stretch and hold a spring 0.1 m from its equilibrium position. a. assuming the spring obeys hooke's law, find the spring constant k. b. how much work is required to compress the spring 0.5 m from its equilibrium position? c. how much work is required to stretch the spring 0.6 m from its equilibrium position? d. how much additional work is required to stretch the spring 0.1 m if it has already been stretched 0.1 m from its equilibrium? a. kequals 600

If water vapor with the mass of 35.0 grams is cooled and condensed into water in a closed system such as a closed glass jar, what is the mass of the water after the water vapor completely condenses? a) 34.5 grams b) 35.0 grams c) 35.5 grams d) the mass cannot be determined without knowing the volume