NYJC 2022 Prelim P2 Guide

NYJC 2022 9749/02/J2PRELIM/22 [Turn over NANYANG JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CLASS TUTOR’S NAME CENTRE NUMBER S INDEX NUMBER PHYSICS 9749/02 Paper 2 Structured Questions 13 September 2022 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, class and tutor’s name in the spaces at the top of this page. Write in dark blue or black pen on both sides of the paper. You may use a HB pencil for any diagrams, graphs. Do not use staples, paper clips, glue or correction fluid. The use of an approved scientific calculator is expected, where appropriate. Answer all questions. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use 1 / 8 2 / 8 3 / 8 4 / 8 5 / 9 6 / 11 7 / 8 8 / 20 Total / 80 This document consists of 22 printed pages.

2 NYJC 2022 9749/02/J2PRELIM/22 Answer all the questions in the space provided. 1 (a) A ball leaves the edge of a table with a horizontal velocity v, as shown in Fig. 1.1. The height of the table is 1.25 m. The ball travels a distance of 1.50 m horizontally before hitting the floor. Air resistance is negligible. Calculate, for the ball, (i) the horizontal velocity v as it leaves the table, v = m s−1 [2] (ii) the velocity just before it hits the floor. velocity = m s−1 [2] Fig. 1.1 ux = v , uy = 0 =xxs u t = vt [1] =+ 210 2 ys at  = + 211.25 0 (9.81)2 t [1] 1.50 = v (0.505) Hence v = 2.97 m s-1[1] =+ 22( ) ( )yxv v v [1] = + = + 0 (9.81)(0.505)yyv u at = 4.95 m s-1[1] = 5.77 m s-1[1]

3 NYJC 2022 9749/02/J2PRELIM/22 [Turn over (b) A second ball leaves the edge of the table with a horizontal velocity 2v. (i) State and explain whether the time take n to hit the floor is the same or different compared to the first ball. [2] (ii) Describe the variation of the vertical component of velocity if air resistance is not negligible. [2] [Total: 8] Since both ball initial velocity for the vertical component is zero, the height is the same and same acceleration of free fall, the time taken is the same. The vertical component of velocity is increasing at a decreasing rate.

4 NYJC 2022 9749/02/J2PRELIM/22 2 (a) State Newton’s Second Law of motion. [1] (b) A jet of water hits a vertical wall at right angles, as shown in Fig. 2.1. The jet of water has density ρ, cross-sectional area A, and hits the vertical wall with impact velocity u. The water then runs down the w