Turn on thread page Beta
    • Thread Starter
    Offline

    3
    ReputationRep:
    A scale reads 0.4 mg
    What is the force acting on the scale if the gravitational field strength is 9.8?

    I calculated 3.92 * 10^-6 N
    But apparently the anwer is 3.92 * 10^-3
    I'm not sure if the answer is just wrong or I'm calculating it incorrectly

    0.4 mg = 4 * 10^-7 kg
    Mass in kg * gravitational field strength = force
    Therefore
    4 * 10^-6 * 9.8 = 3.92 * 10^-6 N
    Offline

    10
    ReputationRep:
    (Original post by AustinKingsley)
    A scale reads 0.4 mg
    What is the force acting on the scale if the gravitational field strength is 9.8?

    I calculated 3.92 * 10^-6 N
    But apparently the anwer is 3.92 * 10^-3
    I'm not sure if the answer is just wrong or I'm calculating it incorrectly

    0.4 mg = 4 * 10^-7 kg
    Mass in kg * gravitational field strength = force
    Therefore
    4 * 10^-6 * 9.8 = 3.92 * 10^-6 N
    Take the mass in grams
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by stoneroses2828)
    Take the mass in grams
    Why does it need to be grams?
    Offline

    22
    ReputationRep:
    (Original post by AustinKingsley)
    Why does it need to be grams?
    You've converted wrong. 1MILI gram is one thousandth of a kilogram. I.e. 1mg = 1*10^3 kg hence 0.4mg = 0.4*10^-3kg.

    how do you convert 0.4mg to kg? I'm confused by your working.
    Posted on the TSR App. Download from Apple or Google Play
    Offline

    7
    ReputationRep:
    (Original post by stoneroses2828)
    Take the mass in grams
    SI units for mass is kilograms bro
    Offline

    9
    ReputationRep:
    (Original post by BTAnonymous)
    You've converted wrong. 1MILI gram is one thousandth of a kilogram. I.e. 1mg = 1*10^3 kg hence 0.4mg = 0.4*10^-3kg.

    how do you convert 0.4mg to kg? I'm confused by your working.
    Actually 0.4mg isnt 4*10^-4 kg. Its 4*10^-4g. So therefore 0.4mg = 4*10^-7kg
    Offline

    22
    ReputationRep:
    (Original post by Rhiaaaaa)
    Actually 0.4mg isnt 4*10^-3 kg. Its 4*10^-3g. So therefore 0.4mg = 4*10^-6kg
    I meant that, lol.
    Posted on the TSR App. Download from Apple or Google Play
    Offline

    9
    ReputationRep:
    (Original post by AustinKingsley)
    A scale reads 0.4 mg
    What is the force acting on the scale if the gravitational field strength is 9.8?

    I calculated 3.92 * 10^-6 N
    But apparently the anwer is 3.92 * 10^-3
    I'm not sure if the answer is just wrong or I'm calculating it incorrectly

    0.4 mg = 4 * 10^-7 kg
    Mass in kg * gravitational field strength = force
    Therefore
    4 * 10^-6 * 9.8 = 3.92 * 10^-6 N
    Answer is 4*10^-7 * 9.8 = 3.92*10^-6 N
    • Thread Starter
    Offline

    3
    ReputationRep:
    (Original post by Rhiaaaaa)
    Actually 0.4mg isnt 4*10^-4 kg. Its 4*10^-4g. So therefore 0.4mg = 4*10^-7kg
    So the mark scheme must be wrong?
 
 
 

1,035

students online now

800,000+

Exam discussions

Find your exam discussion here

Poll
Should predicted grades be removed from the uni application process
Useful resources

Study tools

Rosette

Essay expert

Learn to write like a pro with our ultimate essay guide.

Thinking about uni already?

Thinking about uni already?

See where you can apply with our uni match tool

Student chat

Ask a question

Chat to other GCSE students and get your study questions answered.

Creating

Make study resources

Create all the resources you need to get the grades.

Planner

Create your own Study Plan

Organise all your homework and exams so you never miss another deadline.

Resources by subject

From flashcards to mind maps; there's everything you need for all of your GCSE subjects.

Papers

Find past papers

100s of GCSE past papers for all your subjects at your fingertips.

Help out other students

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.