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hey, are you sure that the answer to 3-is D notA17. Many hand held devices such as smartphones and tablet computers containaccelerometers. These allow changes in orientation of the device to be tracked.A student models a simple accelerometer by attaching a small mass on a string to theroof of a car.(a) (i)Complete a free body force diagram for the mass when the car starts moving.[2]Tension to North-East as you look at the page, Weight down, any others?(ii) Draw a vector diagram, in the space below, to show how the resultant force onthe mass is produced.[2]NOT A CLUE(iii) When the string is at 7 degrees to the vertical, show that the acceleration of the car is 1 m s^-19.81sin7 = 1.2? NOT SURE(b) Sketch the positions of the mass and string when the car is moving in the samedirection and is:(i) moving with constant velocity[1]Vertical(ii) undergoing a much greater acceleration than in (a)(iii)[1]Higher than (a)(iii) on the left side.(iii)deceleration[1]Up on the right side(these explanations are a bit rubbish, hopefully you know what I mean)(c) Explain why the string would not become horizontal, however great the acceleration.[2]There is always a vertical component/weight down. (2 marks?...)(d) Suggest why many devices contain 3 accelerometers, arranged at right angles toeach other[1]Each accelerometer covers a plane of motion (as if it were X,Y,Z axis on a graph)18 Two balls, one solid, one hollow blah blah blahThe two balls dropped, shows the Velocity/Time graphs.(a) State how the graphs show that neither ball reaches terminal velocity.[1]Terminal velocity is where it has reached maximum velocity and so would be a horizontal line on the graph. There is no horizontal line.(b) (i) By drawing a tangent to the graph, to the show that the acceleration of the hollow ballat time t:0.60 s is about 7 m s^-2.[2]Draw tangent, calculate gradient. Can't do too accurately on computer.(ii) Show that the resultant force on the hollow ball at t:0.60s is about 0.02 N.mass of hollow ball: 2.4 g[2]F=ma (need a from (i))(iii) Show that the drag force on the hollow ball at t:0.60s is about 0.01 N. Youmay neglect upthrust.[2]Sub into stoke's law equation(iv) Demonstrate that the Stoke's law force is not sufficient to produce this dragforce.[2]radius of hollow ball: 2.0 cmviscosity of air: 1.8 x 10-s Pa s(c) The diagram shows the air flow around the hollow ball as it falls.(i) Add labels to show laminar flow and turbulent flow.[1]Label the flows accurately(ii) Suggest why the drag is much greater than the Stoke's law force[1]The turbulence causes additional drag(d) Without further calculation, use the graph to describe the motion of the solid ball.[3]
hey, are you sure that the answer to 3-is D notA
Thank you.![]()
You've done so much of hard work..No Problemo
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