A skateboarder rolls 25 m down a hill that descends at an angle of 20° with the horizontal. Find the horizontal components of the skateboarder.

Write short note on the following ; collision theory, rotation angle and angular velocity, centripetal acceleration, coriolis force, and newton's law of gravitation.

Acarpenter builds an exterior house wall with a layer of wood 2.9 cm thick on the outside and a layer of styrofoam insulation 2.3 cm thick on the inside wall surface. the wood has k=0.080w/(m⋅k), and the styrofoam has k= 0.010 w/(m⋅k). the interior surface temperature is 19.0 ∘c , and the exterior surface temperature is -15.0 ∘c . a.)what is the temperature at the plane where the wood meets the styrofoam? celsius b.)what is the rate of heat flow per square meter through this wall? /m^2

Smallest intensity of a stimulus that you can detect 50 percent of the time is