# AP Physics 1: 1.3 Object Interaction and Forces

Hi there. We'd like to wave hello to you, but the internet isn't letting us. So instead, accept this fun question about waves and physics! It's *almost* the same thing, right?

AP Physics 1 | Object Interaction and Forces |

Language | English Language |

Science Practice 5 | Performing data analysis |

### Transcript

marks displacement and which marks acceleration here your potential answers

It will answer this question There are a few important

things to remember First thing to remember is that calculus

is fun Just keep repeating that to yourself over and

over until you really start to believe it We also

need to remember that velocity is the slope of the

plot for displacement versus time and acceleration is the slope

of the plot for velocity versus time Oh we almost

forgot the third thing to remember when plotting the slopes

of waves like this is that the slope of a

sine wave is a co sign way So in the

slope of a co sign wave is an inverse sine

wave a negative sign Wake now that we've got all

this down let's just take a look at our first

plot This first part sure looks like a co sign

Wave tow us So if this is the plot for

velocity and velocity is the slope for displacement versus time

than the plot for disco placement will be a sine

wave if we look at our three choices will see

that plot is a co sign Wave b is a

negative sign wave and see is a sine wave also

looking at our original plot for velocity the second part

of it the flat line is a constant negative value

right Well after all the whole thing is below zero

on the y axis So philosophy is a constant negative

value in this plot the displacement plot has to include

a segment with a constant negative slope and plot c

is the only one that fits the bill Now remember

what we said earlier Acceleration is the slope for velocity

If velocity kicks off with a cho sun wei acceleration

starts with a negative sign and just to be clear

that's s i n e s i g and also

the slope of a flat line is zero So the

acceleration plot should also be zero for the second segment

Looking over our plot options we only have one negative

Sine wave and only one with a segment that has

a flat line of zero Lucky for us they're both

part of a plot B If we take all that

we just did Well we'll see The correct answer is

option d plot See mark's displacement while plot b marks

acceleration that was a hard one Clearly waves and physics

can be tricky very very tricky but they're usually safer 00:02:24.17 --> [endTime] than waves in the ocean Please