Daniel Huang

Review: This is what Albert Einstein did when he was a child. x - 2 = 5 x = ? 159 + x = 190 x = ? 3 x = 216 x = ? x /3 = 300 x = ?

Physics is one of the Science subject that also use Mathematics. Today we are going to talk about "Speed and Acceleration". Speed and Acceleration Definition: Speed is the rate of change of position of an object in any direction. While acceleration is rate at the velocity changes with time, in terms of both speed and direction. Questions: 1. A dog runs 100 m in 12.5 seconds, find the speed You have the triangle formula: So, Distance = 100 m. Time = 12.5 seconds Speed = Distance/Time Speed = 100 m / 12.5 s Speed = 8 m/s. The unit of speed is m/s. 2. We are doing a balloon powered car project. The balloon powered car moves with the distance 1.64 m and the time taken is 4 seconds. Find the speed. Remember the triangle up there! So, Distance = 1.64 m. Time = 4 seconds. Speed = 1.64 m / 4 s Speed = 0.41. Now let's go to the Acceleration. 1. What is the acceleration of a subway train that speeds up from 6 m/s to 12 m/s in 2 s? The equation is: Acceleration = Change in speed / T

 1. Solve this question, round this off to nearest whole number. Answer: 10, why? Comment down below! 2. The n th term of a sequence T n = (2 n + 1) ². Find the difference between the 99th and the 98th term. Answer: (2(99) + 1) ² = 39601 (2(98) + 1) ² = 38809 39601 - 38809 = 792 3. The sum of 3 consecutive even numbers are 222. Find the numbers. Answer:  We have the clue: Let x be the 1st number. x + ( x + 2) + ( x + 4) 3 x + 6 = 222 3 x  = 222 - 6 3x = 216 x = 216 / 3 x = 72 72 + 2 = 74 74 + 2 = 76 72 + 74 + 76 = 222. So the answer is 72, 74 and 76.