l. A car changed its speed from 36 km/hr to 72 km/hr in 10 sec. Calculate the car's acceleration. Convert your answer to m/s. 2. A car changed its speed from 36 km/hr to 54 km/hr within 10 seconds. Calculate the car acceleration. 3. A truck moved 7 m/s in 1 sec and then in 2 sec at a speed of 9 m/s. Calculate the acceleration. For questions 4-6. A car is moving 70 kphr West and a van is traveling 70 kph, East. 4. Are their speed the same? 5. Do they have the same velocity? 6. Can 80 kph be a speed at the same time a velocity? 7. George walks to a friend's house. He walks 750 meters North, then realizes he walked too far. He turns around and walks 250 meters South. The entire walk takes him 13 seconds. What is his speed per second? 8. In problem #7, what was George's velocity in meters per second? (hint: draw a picture to find his displacement)