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calculusxy
 one year ago
If the speedometer of a car reads a constant 40km/hr, can you say the car has a constant velocity? Why or why not?
calculusxy
 one year ago
If the speedometer of a car reads a constant 40km/hr, can you say the car has a constant velocity? Why or why not?

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calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0@Michele_Laino This is like basic physics.

alekos
 one year ago
Best ResponseYou've already chosen the best response.1velocity is defined as speed and direction

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4I think that we can only say that the magnitude of our velocity is 40 Km/h

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4namely, the motion of our car can be a uniform circular motion

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4I think no, since as @alekos as well said the velocity is a vector quantity, which is defined by a speed or magnitude and a direction

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0So since it doesn't have a specific direction it cannot be considered as a "constant velocity," even though it has a constant speed?

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4yes! That's right!

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0I have more questions, since I like to make sure many things. :)

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0What two controls in a car can use a change in speed?

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0I wrote the gas and brake pedals. But I am not sure if I should include the steering wheel, since it might change the velocity as well.

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4I think that you have to include the steering wheel, since by means of the steering wheel we can bend the trajectory of our car, so we can change the velocity of our car

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0So do i write the two pedals (gas and brake) and the steering wheel?

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4yes! I think so!

sweetburger
 one year ago
Best ResponseYou've already chosen the best response.0I agree that the steering wheel would cause a change in direction and therefore could have affect on the velocity

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0Thanks for the continuous help. Next question: What quantity describes how quickly you change how fast you're traveling?

sweetburger
 one year ago
Best ResponseYou've already chosen the best response.0Acceleration? right?

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0Yes that's what I thought. But I am not quite sure.

sweetburger
 one year ago
Best ResponseYou've already chosen the best response.0change in velocity over time*

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4right! The steering wheel can produce a centripetal acceleration which is acting on our car @sweetburger

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0@Michele_Laino For this question:What quantity describes how quickly you change how fast you're traveling? Would the answer be "acceleration"?

alekos
 one year ago
Best ResponseYou've already chosen the best response.1Previously you asked "What two controls in a car can change the speed?" (not velocity) that would only be brake and gas pedal.

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4yes! I think so, since the acceleration, as a number, is the change in speed

sweetburger
 one year ago
Best ResponseYou've already chosen the best response.0@alekos I think you are correct considering it is only asking for change in speed.

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4you are right! @alekos

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0What is the acceleraiton of a car that travels in a straight line at a constant speed of 100km/hr?

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0the acceleration would be 100km/hr since it is travels in a straight line

sweetburger
 one year ago
Best ResponseYou've already chosen the best response.0if it is at a constant speed of 100km/hr there is no change in velocity so 0/t = 0

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4if the speed is constant, then the acceleration as a simple number, and not as a vector quantity, is zero

sweetburger
 one year ago
Best ResponseYou've already chosen the best response.0the velocity must change over a specific period of time to find a acceleration value

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4the acceleration as a vector quantity, since the motion is along a straight line, is the null vector

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0What is the acceleration of a car moving along a straight line path that increases its speed from zero to 100km/hr in 10 seconds?

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0Yes that's why i deleted it

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4we have: 100 Km/h= 27.78 m/sec so acceleration is: 27.78/10=2.778 m/sec^2

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0yeah i was overlooking the "per hour" thank you for correcting that

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0BY how much does the speed of a vehicle moving in a straight line change each second when it is accelerating at 2km/hr (two kilometers per hour per second; that is every second, the velocity is increasing two kilometers per hour.)

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4after a time t (seconds), the requested change is 2*t Km/h

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0I don't quite understand

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4by definition, acceleration a is given by the subsequent formula: \[a = \frac{{\Delta v}}{{\Delta t}}\] so we have: \[\Delta v = a\Delta t\]

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4now, a= 2(Km/h)/sec and if \Delta t= 1 seconds, then we can write: \[\Delta v = a\Delta t = 2 \times 1 = 2\frac{{Km}}{h}\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0ansur at my fb : https://www.facebook.com/ParthKohli

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0What does \[a \Delta t\] mean

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0Moving on to the next question: Why does the unit of time never twice in the unit of acceleration?

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0Would it be that the acceleration is found by dividing the velocity by time: \[(distance / time) / time => distance / time^2\]

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4\[a\Delta t\] is the change in speed

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0So how would i calculate the speed?

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0QUestion: Calculate the speed (in m/s) of a skateboarder who accelerates from rest for 3 seconds down a ramp at an acceleration of 5/m^2.

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4here we have to apply this formula: \[v = a\Delta t = 5 \times 3 = ...m/\sec \]

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0so for this question would we do: \[V_f = V_i + (acceleration \times time)\]

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4yes! nevertheless the initial speed is zero, since the skateboarder is starting from the rest

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0V_i = 0 (initial velocity) acceleration = 5 m / s^2 time = 3 seconds \[V_f = 0 + (5 \times 3)\]

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0THANK YOU SO MUCH!!! Last question: Which has more acceleration when moving in straight line: car increasing its speed rom 5060km/hr or a bicycle that goes from 0 to km/hr in the same time? Why?

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4bycicle goes from 0 to ?

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4if we consider a time interval \Delta t measured in hours, then the acceleration of the car is: \[{a_{CAR}} = \frac{{\left( {60  50} \right)}}{{\Delta t}} = \frac{{10}}{{\Delta t}}\;\frac{{Km}}{{{h^2}}}\] whereas the acceleration of the bycicle is: \[{a_{BYCICLE}} = \frac{{\left( {10  0} \right)}}{{\Delta t}} = \frac{{10}}{{\Delta t}}\;\frac{{Km}}{h}\]

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4oops.. \[{a_{BYCICLE}} = \frac{{\left( {10  0} \right)}}{{\Delta t}} = \frac{{10}}{{\Delta t}}\;\frac{{Km}}{{{h^2}}}\]

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0So these are both the same right?

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4sorry for my english: bicycle*

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4yes! They are the same

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0Thanks!!!!!! I honestly love your help, you have been with me for the past hour!! OMG no one, believe me does that much, except for you!

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0Sorry, but can you explain me the answer for the question: "BY how much does the speed of a vehicle moving in a straight line change each second when it is accelerating at 2km/hr (two kilometers per hour per second; that is every second, the velocity is increasing two kilometers per hour.) "

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0I still didn't get it :(

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4the speed change as function of time interval \Delta t, is given by the subsequent formula: \[\Delta v = a\Delta t\] where a is the acceleration

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4in our case, we have: \[a = 2\frac{{Km/h}}{{\sec }}\]

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4so, if we consider a time interval \Delta t = 1 second, then after that time interval the speed change is: \[\Delta v = a\Delta t = 2 \times 1 = 2\frac{{Km}}{h}\] namely the requested speed change is: 2 Km/h

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0So the answer itself is 2km/hr ?

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0Thank you! And for the question with the speed from 0 ti 100km/hr in 10 seconds how did you get 27.78 m/sec

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4since we have to divide by 3.6, namely 100/3.6 = 27.78 (approximated value)

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4more explanation, we have: \[1\frac{{Km}}{h} = \frac{{1000}}{{3600}}\frac{m}{{\sec }} = \frac{1}{{3.6}}\frac{m}{{\sec }}\]

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4therefore: \[1\frac{m}{{\sec }} = 3.6\frac{{Km}}{h}\]

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0Thank you soo.... much! May I know what times you are available in OS so that if i need help in physics/math, I can come and ask for your help?

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4I'am available from 16:00 (Italy time zone)

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0Well I am in NY so what would be the time in EST?

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4I think 166= 9:00 am

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4sorry: 166= 10:00 am

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0oh okay so it's like 8pm in italy now?

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4yes! at the moment it is 19:57 from me

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0you use the military time a lot?

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0or the 24 hour standard clock?

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.4I use the standard 24 hour clock

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0okay b/c i use am and pm. anyway, thank you so much for your help. i REALLY appreciate it :)
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