Make a graph comparing velocity

  • Thread starter Thread starter Malicious
  • Start date Start date
  • Tags Tags
    Graph Velocity
AI Thread Summary
The discussion focuses on solving a physics problem involving average speed and distance traveled during a trip with a rest stop. The average speed is given as 77.8 km/h, while the constant driving speed is 89.5 km/h, with a 22-minute break factored in. The method to find the time spent driving involves setting up the equation for average velocity as the change in distance divided by the change in time. By substituting the known values and solving for time, it is determined that the driving time is approximately 2.44 hours, resulting in a total distance of 218.2 km. The conversation emphasizes the straightforward nature of the calculations once the correct approach is established.
Malicious
Messages
15
Reaction score
0
I currently have two problems left that I have to complete for physics, but I can't seem to figure out how to solve them.
--------------------------------------------------------------------
1. A person takes a trip, driving with a constant speed of 89.5 km/h except for a 22.0-min rest stop. If the person's average speed is 77.8 km/h, how much time is spent on the trip and how far does the person travel?

(NOTE: I do not need the answer, I just need to know how to solve it)
---------------------------------------------------------------------
2. Make a graph comparing velocity (velocity-time graph, 2 curves)
(box=car, circle=big rolling marble/ball/object)

http://img83.imageshack.us/img83/4576/problemte3.gif
 
Last edited by a moderator:
Physics news on Phys.org
They give us an average velocity of 77.8 km/h. We know that average velocity is (change in distance)/(change in time). so start from there

77.8 = (change in distance)/(change in time)

the change in distance is 89.5 km/h * X (x = some number of hours that he spent driving). the change in time is X + (22/60) (the time he spent driving + the break he took). since the velocities are given in hours, the break should be converted from minutes into hours.

so that gives...

77.8 km/h = (89.5 km/h)X / (X+(22/60))
x = 2.44 hours

to get the distance traveled simply take 89.5*x to get 218.2 km
 
Wow, its so simple. Thanks for your help, BishopUser.
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top