101 Revision: Kinematics

Fairly recently, I took in a few of my sister's classmates for extra Physics lessons, and I was doing Kinematics with them, as part of the infamous "Physics Chapter 2", which I struggled with a bit myself when I first tried to self-study during the old days, but I got around it anyway.

So, to lighten things up in this otherwise abstract chapter, I just devised a few questions titled "Meal or No Meal", derived from the popular game show, minus the metal briefcases, models and mysterious banker. The questions require use of the 4 kinematics equations, to decide whether the characters in questions will have "Meal or No Meal?"

So, are you game? Here are the questions...

  1. Abu just got a promotion and he decided to treat himself to a delicious meal at the Sangat Jauh Restaurant, which (judging by the name) is on the other side of town. However, as luck would have it, he had to work overtime on that day. Therefore, he had to rush to dinner, and drove his car at 35 m/s, which is way over the speed limit. At Jalan Banyak Mata, he noticed that there is a speed camera ahead of him, and the speed limit there was 20 m/s. He also notes that if he brakes now, he will reach the speed camera in 20 seconds. If Abu kena saman, he would have forget about the wonderful dinner since it would cost him a lot of money. Given that his car has a deceleration of 0.9 m/s/s, your question is… Meal or No Meal?
  2. Ben is driving down to Lukut to visit a friend, and since there was not much traffic, he drove at 30 m/s. Suddenly, a cow crossed the road 500 metres in front of his car, and Ben hits his brakes, which decelerated the car at 0.8 m/s/s. If Ben hits the cow, the nearby villagers will have beef rendang for dinner that night. Otherwise, they will only have ulam… sorry, I heard it’s called salad now… for dinner. Therefore, you have to tell the villagers whether they’ll have… Meal or No Meal?
  3. Chow just bought a new toaster, but little did he know that the toaster had a slight defect. Upon toasting the bread, the toaster launches the bread with an initial velocity of 8 m/s directly upwards and the ceiling is 3 m above the toaster. On the first morning of its use, he decided to make breakfast with it. If the toasted bread hits the ceiling, the bread will crumble and his breakfast will be ruined. Chow can react and catch the bread only 0.8 seconds after the launch, and the deceleration due to gravity is 10 m/s/s. Once again, the question is… Meal or No Meal? (hint: take the smaller answer)
  4. Dinesh is trying to get to the Not Open 24 Hours Fried Chicken fast food restaurant in his area just before it closes. He is approaching a traffic light which he knows will turn red in 10 seconds, but don’t ask me how he knows that. He was initially going at 18 m/s. Since he is a law-abiding citizen, unlike Abu, he can and will accelerate only up to 20 m/s. In addition, the traffic lights are 180 metres in front of him. Luckily, he did the calculations in time, and was able to do the right thing, i.e., break no traffic regulations. Ultimately, if he did not make it past the traffic lights, he would have to go hungry since the store will be closed by the time he gets there. For the last time… Meal or No Meal?


SY said...

Anyway the wis.ntu page updated already and thank god they received my documents.