Aladder 16 m. long rests against a frictionless wall and makes a angle of 60° with the horizontal. a 180 n. man is on the ladder, m t the top. what horizontal force is needed at the bottom of the ladder in on to prevent. the ladder from slipping? neglect the weight of the ladder.

Current enters a circuit at a: 1.positive terminal 2.negative terminal 3.low potential side 4.resistor

A150 w lamp emits light of wavelength 590 nm uniformly in all directions. what is the photon flux (photons per unit area per unit time) on a small screen at a distance 2.3 m from the lamp? assume the photons are uniformly distributed over the surface of a sphere of radius 2.3 m.

An object with initial temperature 130 ∘ f is submerged in large tank of water whose temperature is 50 ∘ f . find a formula for f ( t ) , the temperature of the object after t minutes, if the cooling constant is k = − 0.2 . remember newton's law of cooling (the rate of change of temperature with respect to time is equal to k times the difference between the temperature of the object and the surrounding temperature) ! : )