D Question 7 5 pts A force of magnitude 4,500 N is required to bring a car to rest from an initial speed of 70 km/h in a time interval of 5.5s. What is the mass of the car? D Question 8 5 pts A 30 kg object is being lowered on a rope and is measured to have an upward acceleration of 1.8 m/s2. What is the tension in the rope? D Question 9 5 pts A flatbed truck can decelerate at 4 m/s2. In order that a crate on the bed of the truck will not slide into the cab, what should be the minimum coefficient of static friction between the crate and the truck bed