Displacement Calculation for a Moving Cyclist

  • Thread starter Thread starter FlipMC
  • Start date Start date
AI Thread Summary
A cyclist traveling at an average velocity of 5.9 m/s for 1.2 hours needs to calculate displacement. The correct approach involves converting 1.2 hours to seconds, resulting in 4320 seconds. Using the formula for displacement, d = velocity × time, the calculation should be d = 5.9 m/s × 4320 s, which equals 25,488 meters or 25.5 km. The confusion arises from misinterpreting the units and the distinction between displacement and velocity. The final correct displacement is approximately 26 km to the west, aligning with the textbook answer.
FlipMC
Messages
12
Reaction score
0

Homework Statement



A cyclist is traveling with an average velocity of 5.9 m/s[W]. What will be his displacement after 1.2 h?

Homework Equations



d = v1▲t+½a▲t^2 ?

The Attempt at a Solution



Vavg = 5.9 m/s
▲t = 1.2 x 60 = 72 m/s

What I did was use d = v x t and I got 424m/s, which is 1, 526.4 km/h. But that's way off from my the textbook's answer which is, 26km[W]..

It sounds so easy but honestly, I'm going crazy trying to figure it out LOL :redface:.
 
Physics news on Phys.org
Cyclist is traveling with uniform velocity.
So the displacement = velocity*time.
Convert 1.2 hours to seconds
 
You got to get everything in the same units. We have velocity in m/s so we want time in seconds.

1.2 hours = 72 minutes = 4320 seconds

Then just use:

Distance = Velocity*Time
 
Thanks guys.
So I did D = 5.9m/s x 4320 which equaled to 25, 488m/s?
Then, to change it back to km/h, times 3.6 then it equaled 91, 756.8?!
What am I doing wrong? :(
 
In the problem displacement is asked, not the velocity.
 
Hm, right.. AMG, I still don't get this :'(
 
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