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2024PPp1q6 Ball falling with inital velocity greater than terminal velocity

Evan Toh
Mar 18
1 min read

Updated: Mar 19

Instead of the usual ball release from rest, this question states that the ball has an initial velocity greater than terminal velocity in the air.

There are a few scenarios which are possible.

object moving in vacuum at high speed entering air (e.g. meteor entering Earth's atmosphere)
object is thrown down from a high altitude at high speed
parachute is opened and the speed decreases till terminal velocity
stone falling with high speed in air hits the water and speed decreases
etc

View the video for the explanation.

Question: 2024PPp1q6

Video 03 - Finding resultant velocity on boat or plane with wind (updated)

Evan Toh
Mar 14
1 min read

Updated: Mar 19

Instead of the usual vector diagram involving forces, these questions involve speed in a specific direction, which is velocity.

Velocity is a vector quantity, which has both magnitude and direction.

Hence we can apply the vector diagram (parallelogram method or tip-to-tail method) to these questions.

Question 01

Question 02: 2012P1Q2

Question 03: 2021PPp1Q1

2023SPp1q3 What is the air resistance when the speed is doubled?

Evan Toh
Mar 9
1 min read

This question is challenging to students as there are many information given. But it is actually quite straight forward when you save one thing at a time.

In this question, it is given that speed doubles, air resistance increases by four times. The actual relationship is speed is directly proportional to speed^2.

This question can be more challenging if this is given instead or that a random other speed is given. Watch the second part of the video to understand this deeper, especially for Pure Physics students.

What the video tutorial.

Question: 2023SPp1q3

Answer: Option A