A1.6 kg ball at the end of a 1.1 m string swings in a vertical plane. at its lowest point the ball is moving with a speed of 17 m/: s (a) what is its speed (in m/s) at the top of its path? 4.64 xm/s (b) what is the tension (in n) in the string when the ball is at the bottom and at the top of its path? bottom of its path 436.04 top of its path

Under conditions for which the same room temperature is maintained by a heating or cooling system, it is not uncommon for a person to feel chilled in the winter but comfortable in the summer. provide a plausible explanation for this situation (with supporting calculations) by considering a room whose air temperature is maintained at 20â°c throughout the year, while the walls of the room are nominally at 27â°c and 14â°c in the summer and winter, respectively. the exposed surface of a person in the room may be assumed to be at a temperature of 32â°c throughout the year and to have an emissivity of 0.90. the coefficient associated with heat transfer by natural convection between the person and the room air is approximately 2 w/m2 â‹…â‹… k. what is the ratio of the thermal resistance due to convection to the thermal resistance due to radiation in the summer? what is the ratio of thermal resistances in the winter

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?

The free body diagram shows a box being pulled to the left up a 25-degree incline. the magnitude of the normal force is