Kayak A is initially at rest and then person B leaps off the kayak A with a relative velocity vB/A and lands in kayak C with person D. Each kayak has a mass of 40 kg, the mass of person B is 30 kg and the mass of person D is 25 kg. After person B leaves kayak A, the velocity of kayak A is 1.86 m/s to the left. After person B lands in kayak C the velocity of kayak C is 0.44 m/s to the right. Assuming the kayaks will not displace in the y direction, determine:.

Consider an ordinary, helium-filled party balloon with a volume of 2.2 ft3. the lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. using this fact, we can derive archimedes’ principle, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. assuming that the balloon is at sea level, where the air density is 0.002377 slug/ft3, calculate the maximum weight that can be lifted by the balloon. note: the molecular weight of air is 28.8 and that of helium is 4.

15. give an example for some particles or waves that are moving faster than light in everyday life 16. what is a laser? 17. what is an oscilloscope? 18. what does it means practically that nothing is faster than light in vacuum? 19. what is vacuum?

Two pans of a balance are 24.1 cm apart. the fulcrum of the balance has been shifted 1.33 cm away from the center by a dishonest shopkeeper. by what percentage is the true weight of the goods being marked up by the shopkeeper? assume the balance has negligible mass. answer in units of %.