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ex. 1 Consider the following combinations of signs and values for velocity and acceleration of a particle with respect to a one-dimensional x-axis Velocity Acceleration a) + + b) + c) + 0 d) + e) f) 0 g) 0 + h) 0 If the object is a car moving on an east-west axis with east being positive, describe each situation. Which way is it moving? Is it speeding up, slowing down, etc? ex. 2 An electron moving in a straight line has an initial speed of 3.0 x 105m/s. It speeds up at 8.0 x 1014m/s2. (a) How long will it take to reach a speed of 5.4 x 105m/s? (b) How far will it have traveled in this time? ex. 3 A truck on a straight road starts from rest accelerating at 2.0m/s/s until it reaches a speed of 20m/s. Then the truck travels for 20s at constant speed until the brakes are applied, stopping the truck in a uniform manner in an additional 5.0s. a) How long is the truck in motion? b) What is the average velocity of the truck for the motion described? HW4