PHYS 101 Lecture Notes - Lecture 1: Density
15 May 2018
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Phys 101 Fall 2017 Written Problems #1
Due: Friday, Sept 15, 2017 at 4 PM. Put finished assignment in P101 drop box on 9000 level of Physics
(put into the box that has your tutorial section number as a label).
Please note to get full credit for any written homework assignment you must:
1) Put the assignment name, your full name, your student number, your tutorial section number
(see Canvas for tutorial sections), and TA first name (-1 mark if not done correctly) :
PHYS 101 – Homework #1, Susie Smith, 123456789, D102, Farnaz
2) Show all of your work, clearly and legibly. Use diagrams if necessary. Put #s in at the end.
3) Put a box around your answers.
4) Don’t forget units.
5) If you use more than one page, staple all of the pages together (-1 mark for unstapled
assignments)
Problem 1. Estimation: Are you more human or more bacterium? (4 marks)
Make an estimate for the number of bacteria and human cells in the human body using the sizes below.
Assume both human cells and bacteria are spherical in shape and have the mass density of water. Take
the mass for a typical human to be 70 kg and the total mass of bacteria cells in your body to be 0.3 kg.
So are there more bacteria cells than human cells in your body?
Problem 2: Predators and prey (6 marks)
In the wild, the relationship between predator and prey is a complex game of cat and mouse. In this
question you will answer how far away from a predator should a prey be in order to be able to escape if
a predator is lurking nearby. Our predator is a cheetah, one of the fastest land animals, but it can only
maintain its high speed for a short time after which it gets exhausted. Our prey is a Thomson’s gazelle
that can run at a steady pace for a long time (at least long relative to the cheetah) but its maximum
speed is less than the cheetah. The relevant data are collected in the table below.
Document Summary
Due: friday, sept 15, 2017 at 4 pm. Put finished assignment in p101 drop box on 9000 level of physics (put into the box that has your tutorial section number as a label). Phys 101 homework #1, susie smith, 123456789, d102, farnaz: show all of your work, clearly and legibly. Put #s in at the end: put a box around your answers, don"t forget units, if you use more than one page, staple all of the pages together (-1 mark for unstapled assignments) Estimation: are you more human or more bacterium? (4 marks) Make an estimate for the number of bacteria and human cells in the human body using the sizes below. Assume both human cells and bacteria are spherical in shape and have the mass density of water. Take the mass for a typical human to be 70 kg and the total mass of bacteria cells in your body to be 0. 3 kg.
