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AN oxygen atom is four times as massive as a helium atom. In an expriment of helium atom and an oxygen atom have the same kinetic energy. WHat is ratio V(He)/V(o) of their speed?

A fisherman casts his bait into the river at an angle of 25 degrees. As the line unravels, he notices that the bait and hook reach a maximum height of 1.7 m. What was the initial velocity he launched the bait with?

Oky I am trying to work this problem out myself but I got stuck I have sollution as well I got till this far 1. F = FT - Mu kmg F = 200 - (0:1)(75)(9:8) = 126 N F = ma = F/m = 126=75 = 1:69 m/s2 s = 1/2at2 = 1/2(1:69)(61)2 = 3144 m<---------- I don't get how they got and where they got 61 from v = at = (1:69)(61) = 103 m/s ]<---------- same for here x = v2/2a; a = Mu kg x = (103)2 2(0:1)(9:8) = 5413 xT = 3144 + 5413 = 8:6 km

1. Jason takes of across level water on his jet-powered skis. The combined mass of Jason and skis is 75 kg. The skis have a thrust of 200 N and a coeffcient of kinetic friction on water of 0.1. Unfortunately, the skis run out of fuel after 57 s. What is Jason's top speed? I am just doing sample problems for my test today please help thank you