No prefix: How far does a car move before running out of gas on a road?

  • Thread starter Thread starter ArcherofScience
  • Start date Start date
  • Tags Tags
    Car
AI Thread Summary
A car traveling at 45 km/hr runs out of gas and takes 6.0 seconds to stop. The initial attempt to calculate the stopping distance using the equation x=(vi+vf)/2 * t resulted in an incorrect answer of 135 meters. The correct approach requires converting the initial velocity from kilometers per hour to meters per second, which leads to the accurate distance of 37.5 meters. After making the conversion, the correct answer was confirmed. Proper unit conversion is essential for accurate physics calculations.
ArcherofScience
Messages
36
Reaction score
2
car moving down road...

Homework Statement


A car is moving down a road at 45 km/hr when it runs out of gas. How far does the car move if it takes 6.0s to roll to a stop?

Homework Equations


x=(vi+vf)/2 *t I tried this equation, but I got the answer of 135 m. It says the answer is 37.5 m in the answers given by the teacher.

The Attempt at a Solution



I set it up this way:

vi: 45 km/hr
vf: 0
t= 6.0 s
x=?
x= (45+0)/2 * 6.0 = 135 mI want to know what I'm doing wrong, am I using the wrong equation? Thanks.
 
Physics news on Phys.org


ArcherofScience said:

Homework Statement


A car is moving down a road at 45 km/hr when it runs out of gas. How far does the car move if it takes 6.0s to roll to a stop?


Homework Equations


x=(vi+vf)/2 *t I tried this equation, but I got the answer of 135 m. It says the answer is 37.5 m in the answers given by the teacher.

The Attempt at a Solution



I set it up this way:

vi: 45 km/hr
vf: 0
t= 6.0 s
x=?
x= (45+0)/2 * 6.0 = 135 m

I want to know what I'm doing wrong, am I using the wrong equation? Thanks.
I suspect that you need to convert the velocity to m/sec.
 


yeh it worked, i got the right answer ! :approve: :D

thankyou! :)
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

"How far did the car move while braking?"
Replies
14
Views
2K
How Far Will a Car Coast Up a Hill After Running Out of Gas?
Replies
8
Views
4K
What is the Average Speed and Acceleration of a Car on a Straight Road?
Replies
45
Views
5K
Will the car make it to the top of the hill?
Replies
5
Views
1K
Calculating Separation of Cars in a Convoy Moving at Max Speed
Replies
4
Views
3K
When 2 Cars With Differing Velocities Will Meet
Replies
3
Views
4K
Calculate Car Deceleration and Stopping Distance | Cars Slam on Brakes
Replies
1
Views
2K
Calculating Acceleration of a Car After Braking
Replies
4
Views
1K
How far does the police car travel to catch a speeder traveling at 180 km/hr?
Replies
1
Views
1K
Calculate Distance Traveled: Car Acceleration from 30 km/hr to 88 km/hr in 7s
Replies
7
Views
3K

Hot Threads

Recent Insights

Back
Top