9 questions on derivative applications! please help!

Question 3 (3 points) Kim throws a ball against a wall at time t = D. At time t = 1, it hits the wall and then at time t = 2 it is back where it started. If the average speed of the ball is 10 miles per hour, can you apply the MVT to show that the baseball must be traveling at 10 miles/hr at some point between [0,2]? Question 4 (3 points) Jon received his math grade for algebra. His class average over 10 tests is 89. Can you use the MVT to show that Jon must have received an 89 on one of the 10 tests? \fQuestion 7 (3 points) The temperature of coffee in a large urn fluctuates as coffee is dispensed and more coffee is added. The temperature measured in degrees Fahrenheit is modeled by the function f(t) = 140 + 10 sin(t) where t is measured in minutes. What is the instantaneous rate of change at t = - 2 minutes?Question 8 (3 points} Given a cube with sides x inches, let x(t} = t + 2. What is the instantaneous rate of change of the volume, with respect to time, of the cube at t = 1 second? Question 9 (3 points) Assume a spring is oscillating and the length of the spring can be described as L (t ) = sin (") What is the formula for the instantaneous rate of change of L(t)? 2Question 10 {3 points) Assume a spring is oscillating and the length of the spring can be described as _ mltl . What is the formula for the instantaneous rate of change of L(t)? Question 11 {3 points) A sphere is expanding with time. Assume that the volume of the sphere is V =g , r(t] = t3 + 2. What is the formula for the rate of change of the volume of the balloon, with respect to time