ACJC 2023 J2 H2 Physics Prelim P3_MS

Anglo-Chinese Junior College 2023 H2 Preliminary Exam Paper 3 MS H2 (9749) Physics JC2 2023 Page 1 of 11 Qn Suggested MS 1)a) If sphere A is to move in the opposite direction, speed of sphere B will have to be higher than the initial speed of sphere A which will mean that total kinetic energy after collision has increased, which is not possible b)i) + = + + = + =+ 2.5 2.5 2.5 2.5 2.0 2.0 2.5 2.0 2.5 2.0 0 2.5(3.6) 0 2.5 2.0 9 2.5 2.0 m u m v m v vv vv Relative speed of approach = relative speed of separation =− 2.0 2.53.6 vv 2.5 2.5 2.5 9 2.5 2.0(3.6 ) 9 7.2 0.44.5 = + + −== vv v ii) ,2.5 2.5(0.4) 2.5(3.6) 16.00.5 −−= = = =fi ave kg pppFN tt Using N3L, the force on the 2.0 kg crate is also 16.0 N c)i) + = + +i i f f fKE gpe KE gpe WD 221 1 2.0(3.0)(1.5) (3.0)(9.81)(2.0) (3.0) 0 15.0( )2 2 sin30+ = + + v 2 1 3.4 58.9 1.5 60 1.24 − + = + = v v ms ii) The crate will reach the bottom of the slope with a much higher speed The will result in it experiencing a much larger vertical force as it moves from the slope onto the vertical surface, potentially damaging the tomatoes.

Anglo-Chinese Junior College 2023 H2 Preliminary Exam Paper 3 MS H2 (9749) Physics JC2 2023 Page 2 of 11 2 (a) Electric field strength E at a point is defined as the electric force exerted per unit positive charge on a small stationary test charge placed at that point in the electric field. (b)(i) 2 0 9 2 12 2 4 2 2 10 4 0 104 8 85 10 2 . .( . )( ) − − − =  =  QE r  = 4.94 ×104 N C-1 (ii)

Anglo-Chinese Junior College 2023 H2 Preliminary Exam Paper 3 MS H2 (9749) Physics JC2 2023 Page 3 of 11 (c)(i) (ii) Electric field strength is the negative potential gradient Gradient points in the direction of the greatest change of potential which is the (opposite) direction of the electric field. There is no component of the electric field strength (electric force) parallel to the equipotential line as this will cause a change in electric potential

Anglo-Chinese Junior College 2023 H2 Preliminary Exam Paper 3 MS H2 (9749) Physics JC2 2023 Page 4 of 11 3(a) The magn