Newton's laws of motionIB MYP Physics: Flashcards

Exam questions on Newton's laws of motion

1. A bus travels at a constant velocity of 15 m/s along a straight, level road in Dubai. The driver then brakes hard and the bus slows down quickly. Passengers who are standing are thrown forwards as the bus slows.
   Explain, using Newton's first law, why the standing passengers are thrown forwards when the bus brakes.2 marks
2. A space agency tests a rocket. Burning fuel produces hot gas that the engine pushes out of a nozzle at the back at very high speed. Once the rocket is in space, it accelerates forwards even though there is no air or ground for it to push against.
   Explain how the rocket accelerates forwards in space even though there is nothing for it to push against.2 marks
3. A student investigates how the acceleration of a trolley of mass 0.50 kg depends on the resultant force on it. The trolley runs along a level, low-friction runway and is pulled by a constant force measured with a force sensor. A motion sensor records the acceleration. A resultant force of 0.25 N gave an acceleration of 0.50 m/s², 0.50 N gave 1.0 m/s², and 1.00 N gave 2.0 m/s².
   State the independent variable, the dependent variable and one control variable in this investigation.3 marks