# 0.11 Phy1080: motion -- variable velocity and acceleration  (Page 12/19)

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Since this definition does not specify velocity, it also applies to objects initially moving upward (which is the case with our arrow that was shot upward).

Free fall was demonstrated on the moon by astronaut David Scott on August 2, 1971. He simultaneously released a hammer and a feather from the same heightabove the moon's surface. The hammer and the feather both fell at the same rate and hit the ground at the same time. This demonstrated Galileo's discovery thatin the absence of air resistance, all objects experience the same acceleration due to gravity.

By the way, it is no accident that the value shown for acceleration in Figure 4 matches the value specified for the acceleration of gravity near the beginningof the code in Listing 3 .

Analysis of the code

The code in Listing 3 is very similar to the code in Listing 2 with the addition of the code necessary to estimate the acceleration values on the basisof the slope of the velocity curve.

The code that estimates the acceleration in Listing 3 is so similar to the code that estimates the velocity in Listing 2 that I won't bore you by explaining the code in detail.

However, there is one bit of new code that is worthy of note. Without going into detail as to the reasons why, this procedure is incapable of accuratelyestimating the slope of the velocity curve during the first two time intervals. Therefore, an if statement was written into the while loop to force the acceleration estimate to be zero for the first two timeintervals.

## Acceleration of gravity exercise #2

In the previous exercises, the arrow was shot straight up in the air. However, that is rarely the case. Normally, an arrow is shot in an attempt to strike a targetsome horizontal distance away.

A more realistic scenario

Let's modify our scenario such that the archer shoots the arrow with an initial velocity of 100 feet per second at an angle of45 degrees relative to the horizontal axis. We will compute and plot the horizontal and vertical position of the arrow at uniform increments in time from thebeginning to the end of its trajectory.

Motion of a projectile with uniform acceleration

The following equation describes the straight-line motion of a projectile with uniform acceleration .

d = v0*t +0.5*a*t^2

where

• d is distance in units of distance
• v0 is the initial velocity in units of distance/time
• t is time in units of time
• a is acceleration in units of distance/time^2

As usual, the units for distance, time, velocity, and acceleration must be consistent with one another.

Shooting the arrow straight up

If we shoot an arrow straight up, as was the case in the previous exercises, the initial velocity doesn't have a horizontal component. Instead, the initialvelocity has only a vertical component and the corresponding motion of the arrow has only a vertical component. In other words, the arrow goes straight up and it comesdown in the same spot.

Shooting the arrow other than straight up

However, if we shoot the arrow in a direction other than straight up or straight down, the initial velocity has both a vertical component and ahorizontal component. Therefore, the resulting motion has both a vertical component and a horizontal component.

find the 15th term of the geometric sequince whose first is 18 and last term of 387
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
hmm well what is the answer
Abhi
how do they get the third part x = (32)5/4
can someone help me with some logarithmic and exponential equations.
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
I don't understand what the A with approx sign and the boxed x mean
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
oops. ignore that.
so you not have an equal sign anywhere in the original equation?
hmm
Abhi
is it a question of log
Abhi
🤔.
Abhi
Commplementary angles
hello
Sherica
im all ears I need to learn
Sherica
right! what he said ⤴⤴⤴
Tamia
hii
Uday
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
a perfect square v²+2v+_
kkk nice
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
or infinite solutions?
Kim
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Al
y=10×
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
rolling four fair dice and getting an even number an all four dice
Kristine 2*2*2=8
Differences Between Laspeyres and Paasche Indices
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
how do you translate this in Algebraic Expressions
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
what's the easiest and fastest way to the synthesize AgNP?
China
Cied
types of nano material
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
what is nano technology
what is system testing?
preparation of nanomaterial
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
what is system testing
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
can nanotechnology change the direction of the face of the world
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
how did you get the value of 2000N.What calculations are needed to arrive at it
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