Suppose you swing a ball of mass (m) in a vertical circle on a string of length (l). as you probably know from experience, there is a minimum angular velocity you must maintain if you want the ball to complete the full circle without the string going slack at the top.1. find an expression for the minimum angular velocity using only the terms (g) and (l).2. evaluate the angular velocity in rpm for a 65 g ball tied to a 2.0-m-long string.

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.

Much of the information taught in earth-space science would not be available if it weren’t for our remote sensing abilities. explain two ways our remote sensing strategies contribute to our knowledge of these topics.

(2) (a) you have a simple circuit that consists of only a battery (δvbat=1.5v) and two resistors with resistance r1=10ω and r2=5ω, connected in series with each other. what is the current running through the battery? (b) you re-arrange your circuit so now r2 is attached in parallel to r1 rather than in series. what is the current running through the battery? (c) you add an additional resistor r3=7ω on the same branch as r2. what is the current running through the battery? (d) what is the power dissipated in r3?