9. Ima Speedin puts the pedal to the metal and increases her speed as follows: 0 mi/hr at 0 sec; 20 mi/hr at 2 sec; 40 mi/hr at 4 sec; 60 mi/hr at 6 sec; and 80 mi/hr at 8 sec. What is the acceleration of
Ima's car?

Aspring with a mass of 2 kg has a damping constant 14 kg/s. a force of 3.6 n is required to keep the spring stretched 0.3 m beyond its natural length. the spring is stretched 0.6 m beyond its natural length and then released. find the position of the mass at any time t. (assume that movement to the right is the positive x-direction and the spring is attached to a wall at the left end.)

Astone dropped into a well is heard to strike the water after 8seconds. find the depth of the well if the velocity of sound is 350m/s

The number of passengers who arrive at the platform of a subway station for the 10 am train is a random variable with a mean of 120 and a variance of 16. find the lower bound of the probability that there will be between 100 and 140 passengers (round off to second decimal place).