Ahot metal bar is submerged in a large reservoir of water whose temperature is 75∘f. the temperature of the bar 20s after submersion is 120∘f. after 1min submerged, the temperature has cooled to 100∘f. (a) determine the cooling constant k. k= s−1 (b) what is the differential equation satisfied by the temperature f(t) of the bar? f′(t)= use f for f(t). (c) what is the formula for f(t)? f(t)= (d) determine the temperature of the bar at the moment it is submerged. initial temperature = ∘f

In order for the bug to fly through the air a force has to push the bug forward. identify this force. how does the bug produce

Explain what it means to view something from a frame of reference. provide an example that illustrates your explanation. (4 points)

An charge with mass m and charge q is emitted from the origin, (x,y)=(0,0). a large, flat screen is located at x=l. there is a target on the screen at y position y(h), where y(h) > 0. in this problem, you will examine two different ways that the charge might hit the target. ignore gravity in this problem. 1.assume that the charge is emitted with velocity v(0) in the positive x direction. between the origin and the screen, the charge travels through a constant electric field pointing in the positive y direction. what should the magnitude e of the electric field be if the charge is to hit the target on the screen? express your answer in terms of m, q, y(h), v(0), and l. 2.now assume that the charge is emitted with velocity v(0) in the positive y direction. between the origin and the screen, the charge travels through a constant electric field pointing in the positive x direction. what should the magnitude e of the electric field be if the charge is to hit the target on the screen? express your answer in terms of m, q, y(h), v(0), and l.