Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
    • Thread Starter

    In an experiment a small metal ball is dropped into a cylinder of oil. The time taken forthe ball to fall to the bottom of the cylinder is recorded.

    The experiment is repeated. Which changes to the ball would result in the greatestdecrease in the time it takes to reach the bottom of the cylinder?
    A smaller mass and smaller diameter
    B smaller mass and greater diameter
    C greater mass and smaller diameter
    D greater mass and greater diameter

    The answer is C, why? my textbook says "the drag force isdirectly proportional to the radius of the sphere, anddirectly proportional to the velocity" and also "doubling the ball’sradius makes its terminal velocity four times as great.". It also says larger objects fall faster

    doesnt that mean that making the diameter bigger means increasing velocity (speed at which it will reach bottom will be fast). can someone please explain this? thank you
Submit reply
Turn on thread page Beta
Updated: November 6, 2015
Do you like carrot cake?

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