Apickup truck is carrying a toolbox, but the rear gate of the truck is missing, so the box will slide out if it is set moving. the coefficients of kinetic and static friction between the box and the bed of the truck are 0.250 and 0.500, respectively. starting from rest, what is the shortest time this truck could accelerate uniformly to 36.0m/s (≈ 80.5mph ) without causing the box to slide?

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

Ascientist notices that an oil slick floating on water when viewed from above has many different colors reflecting off the surface, making it look rainbow-like (an effect known as iridescence). she aims a spectrometer at a particular spot and measures the wavelength to be 750 nm (in air). the index of refraction of water is 1.3

This is a form of winter precipitation. it is frozen precipitation falling as ice pellets. snowflakes melt into raindrops as they pass through a thin layer of warmer air. the raindrops then refreeze into particles of ice when they fall into a layer of sub-freezing air near the surface of the earth. this precipitation is called a) hail. b) rain. c) sleet. d) snow.