1) In a certain road accident, a car of mass 1500 kg, traveling south, collided in the middle of an intersection with a truck of mass 7500 kg, traveling west. The vehicles locked and skidded off the road along a line pointing almost exactly southwest. A witness claimed that the truck had entered the intersection at 55 mph. Do you believe the witness? To decide, calculate the speed at which the car must have entered the intersection for this situation to occur. Enter the speed of the car.
2) The sun appears to be moving at a speed of about 240 km/s in a circular orbit of radius about 27000 light-years around the center of our galaxy. The earth takes 1 year to describe an almost circular orbit of radius about 1.5×10^11 m around the sun. What do these facts imply about the total mass responsible for keeping the sun in its orbit? Obtain this mass as a multiple of the sun's mass M.
Detailed step by step solution provided.