Khẩu súng khối lượng 4kg bắn đi một viên đạn theo phương ngang có khối lượng 50 gam với vận tốc 60m/s coi như lúc đầu hệ súng và đạn đứng yên tốc độ giật lùi của súng là

Talia is manufacturing rolls of wire for hanging pictures. she needs a material that is so that it can easily be pulled into wire without breaking.

Matter that emits no light at any wavelength is called

You have two photos of a person walking. one shows the person at the corner of third and main streets, the other shows the person at the corner of tenth and main streets. there are lampposts at every corner in this town, and the first picture shows it to be 10: 32: 00 exactly. the second picture shows it to be 10: 49: 30. you know three facts: (1) all of the clocks are synchronized; (2) there are exactly 12 equal-sized blocks per kilometer in this town; and (3) the streets that cross main in this area are numbered consecutively, with no interruptions. what is the person’s average speed in kilometers per hour?