Go Back   Physics Help Forum > High School and Pre-University Physics Help > Kinematics and Dynamics

Kinematics and Dynamics Kinematics and Dynamics Physics Help Forum

Reply
 
LinkBack Thread Tools Display Modes
Old Aug 22nd 2014, 02:15 AM   #1
Junior Member
 
Join Date: Aug 2014
Posts: 3
Please help me to find these answers, my exam is near.

Hi everyone!I m new member to this forum, I hope it's really useful site..My exam are near and I tried my best to answers these questions but couldn't.I have many questions among them posting 1..will post other..please answer me.
1.Rain drops hitting the side windows of a car in motion often leave diagonal streaks.why?
binod is offline   Reply With Quote
Old Aug 22nd 2014, 05:43 AM   #2
MBW
Senior Member
 
MBW's Avatar
 
Join Date: Apr 2008
Location: Bedford, England
Posts: 668
Vector Addition

Think first what would happen in a stationary car (on a windless day)
The rain drops are coming straight down, relative to the car window, so the streak on the window will be straight down.

Now consider what happens if the car (and thus the window) is moving.
The motion of the raindrop relative to the window is no longer straight down.

Imagine an observer standing at a buss stop (for example).
The observer sees the rain coming straight down and the car moving horizontally
The motion of the raindrop relative to the window is given by adding the straight down motion of the raindrop to the horizontal motion of the car
giving a diagonal motion.
MBW is offline   Reply With Quote
Old Aug 22nd 2014, 06:25 PM   #3
Junior Member
 
Join Date: Aug 2014
Posts: 3
Originally Posted by MBW View Post
Think first what would happen in a stationary car (on a windless day)
The rain drops are coming straight down, relative to the car window, so the streak on the window will be straight down.

Now consider what happens if the car (and thus the window) is moving.
The motion of the raindrop relative to the window is no longer straight down.

Imagine an observer standing at a buss stop (for example).
The observer sees the rain coming straight down and the car moving horizontally
The motion of the raindrop relative to the window is given by adding the straight down motion of the raindrop to the horizontal motion of the car
giving a diagonal motion.

thank u so much..
binod is offline   Reply With Quote
Old Aug 22nd 2014, 06:26 PM   #4
Junior Member
 
Join Date: Aug 2014
Posts: 3
Can we have zero accerlation but non zero velocity?
binod is offline   Reply With Quote
Old Aug 23rd 2014, 06:37 PM   #5
Physics Team
 
ChipB's Avatar
 
Join Date: Jun 2010
Location: Morristown, NJ USA
Posts: 2,320
Originally Posted by binod View Post
Can we have zero accerlation but non zero velocity?
Of course. A car coasting along a road may have zero acceleration and velocity of 60 MPH.
ChipB is offline   Reply With Quote
Reply

  Physics Help Forum > High School and Pre-University Physics Help > Kinematics and Dynamics

Tags
answers, exam, find



Search tags for this page
Click on a term to search for related topics.
Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
Rotational Motion: two answers....both seem valid berniecooke Kinematics and Dynamics 2 Mar 9th 2015 09:21 AM
Can someone check my answers ? Travelling car. shoushanik Kinematics and Dynamics 3 Aug 8th 2014 08:05 AM
Are my answers correct? honestliar Kinematics and Dynamics 1 Oct 26th 2009 11:10 PM


Facebook Twitter Google+ RSS Feed