<p>Ya I can’t figure this out so can someone smart person please help me :D</p>
<p>Imagine that gravity is suddenly turned off in a classroom on the equator. All of the objects in the room, including desks and students, are either bolted or fastened to the floor, which in turn is securely attached to Earth. All objects, that is, except for an eraser that is lying on the missle of the floor. What does the eraser do when gravity is turned off? If you think that the eraser rises then in what direction does it rise in the classroom frame,and how long does it take to reach the ceilling,say 9 ft above the floor?</p>
<p>I would assume that it goes east based on the Earth’s rotation, but idk bout the time. idk if you would use 2(pi)rf to find the velocity (knowing that the earth spins around every 86400 seconds which is what it needs to be in and the radius being 6.38 x 10^6) then i could use V=2(pi)/T which would i think give me my answer…if anyone could correct me please?</p>
<p>No gravity => no forces acting on eraser => eraser moves with constant velocity in the same direction it was going before. Which is tangent to the Earth’s rotation. So I think the eraser should move diagonally upwards (from the classroom’s frame of reference). The tangential velocity with which it moves can be found using centripetal force = mv^2 / r, where v is the tangential velocity (velocity with which the eraser moves), r is the radius of the earth, m is the mass of the eraser.</p>
<p>Of course, a year of doing pointless 30-page labs has made me suck at actual physics, so the above should be taken with a few hundred grains of salt. Plus I forget how to find the centripetal force (I think you’d have to account for both gravity and the normal force, but how would you find the normal force?). And there might be some weird rotational effects I don’t know about, because I’m bad at anything involving rotation.</p>
<p>You’ll have to tell me the answer to this sometime.</p>
<p>ok thanks…My final answer for the question was like 1/(5.something x 10^11) but i forgot to add the 9 feet into the equation which means my answer off and probably got the wrong answer anyways.</p>