PHYS1100 Mechanics Practice Problems 2 Solutions
2025 complete update University of Western Australia
PHYS1100 Mechanics Practice Problems 2
Note on Reading These Solutions: In these practice problem solutions, I have endeavored to include all working steps
(except for trivial algebraic rearrangements). Each question is solved starting from the most fundamental laws, typically found
on your equation sheet. This approach is not reflective of how you would solve problems in practice. In reality, many of
these steps would be done mentally or omitted because you already understand how to handle specific situations. My aim is
to illustrate how the fundamental laws underpin the solutions and to demonstrate the thought process you should quickly go
through before writing down steps that may already incorporate several considerations.
In a written test or exam, you would not waste time writing out these steps; they are included here purely for informational
purposes. To highlight the steps that can be skipped, I have written them in cyan. Feel free to skip these steps, especially in
the simpler early chapters, but ensure you understand the underlying concepts.
1. Example Variation Problem 4.37: A 2650 kg car is subject to an 9.25 kN force that accelerates it in a straight line.
,(a) Starting from rest, how much time will it take the car to reach a speed of 24.2 m/s?
F⃗=
1
, (b) The car then enters a circular turn, where the road exerts an 7.65 kN force to keep the car on its circular path. What’s
the radius of the turn?
F⃗c
Page 2
2025 complete update University of Western Australia
PHYS1100 Mechanics Practice Problems 2
Note on Reading These Solutions: In these practice problem solutions, I have endeavored to include all working steps
(except for trivial algebraic rearrangements). Each question is solved starting from the most fundamental laws, typically found
on your equation sheet. This approach is not reflective of how you would solve problems in practice. In reality, many of
these steps would be done mentally or omitted because you already understand how to handle specific situations. My aim is
to illustrate how the fundamental laws underpin the solutions and to demonstrate the thought process you should quickly go
through before writing down steps that may already incorporate several considerations.
In a written test or exam, you would not waste time writing out these steps; they are included here purely for informational
purposes. To highlight the steps that can be skipped, I have written them in cyan. Feel free to skip these steps, especially in
the simpler early chapters, but ensure you understand the underlying concepts.
1. Example Variation Problem 4.37: A 2650 kg car is subject to an 9.25 kN force that accelerates it in a straight line.
,(a) Starting from rest, how much time will it take the car to reach a speed of 24.2 m/s?
F⃗=
1
, (b) The car then enters a circular turn, where the road exerts an 7.65 kN force to keep the car on its circular path. What’s
the radius of the turn?
F⃗c
Page 2
