Xác định quỹ đạo chuyển động của một chất điểm chuyển động trong mặt phẳng xOy khi bán kính véc-tơ ~r xác định vị trí của chất điểm
đó cho bởi phương trình sau:
r=acos(π/1+t²)x+bsin(π/1+t²)y
trong đó t là thời gian chuyển động, xˆ và yˆ tương ứng là các véc-tơ
đơn vị của các trục Ox và Oy; a, b là các hệ số không đổi.

Which of the following is an example of units for speed

4. a 75.0 g piece of ag metal is heated to and dropped into 50.0 g of water at the final temperature of the mixture is what is the specific heat capacity of silver? 5. a 465 g chunk of iron is removed from petrucci, ralph h.. general chemistry (p. 290). pearson education. kindle edition.

Simon is writing a story about an astronaut whose spacecraft has been boarded by space pirates. the astronaut has her lucky penny in her hand behind her back as the space pirates break into the control room. she has just locked the controls so that the ship is accelerating in the direction of the control room’s ceiling. simon wants the astronaut to use the penny to hit a button on the control panel to turn off the lights and escape. the button is located a short distance behind and below the astronaut’s hands. how should simon use the theory of relativity to describe what the astronaut must do in order to hit the button?