Speed for Remaining Time and Distance

• MysticDude
In summary, the conversation is about a person needing help to check the correctness of their calculations for a trip to an interview 300km away. They plan to drive at 100km/hr, but due to construction work, they had to slow down to 40km/hr for 40km. The question is what would be the least speed needed for the rest of the trip to arrive at the interview on time. Using equations, the person determined that a speed of 128km/hr is needed for the remaining 160km to arrive at the interview at 11:15 AM. They later confirmed that their answer was correct.
MysticDude
Gold Member
Hi people of PF! Okay so I just want you guys to check if my work is correct and if it not, help me fix it :D.

Homework Statement

You are to drive to an interview in another town, at a distance of 300km on an expressway. The interview is 11:15 AM. You plan to drive at 100 km/hr, so you leave at 8:00AM. to allow some extra time. You drive at that speed for the first 100 km, but then construction work forces you to slow to 40km/hr for 40 km. What would be the least speed needed for the rest of the trip to arrive in time for the interview?

GIVEN
Distance for travel is 300km
First hour of travel was at 100km/hr
Second hour of travel was at 40km/hr

Homework Equations

v = d/t where d is the distance and t is the time (1)
d = v*t where v is the velocity (2)
t = d/v (3)

The Attempt at a Solution

Okay so I figured that the total distance traveled is going to be 140km, meaning 160 km are left to travel. I also figured that 2 hours have been used to travel that time, meaning 1:15 hr are left. 1:15hr = 1.25hrs. So by using Equation (1) I get 160km/1.25hr = 128km/hr for the least amount of speed to get to the meeting at 11:15. I want to know if this answer is correct.Any help is greatly appreciated!

Last edited:
No more help needed, I just checked with an on-line tutor and I was correct.

What is "speed for remaining time and distance"?

"Speed for remaining time and distance" is a scientific concept used to determine the velocity at which an object must travel in order to reach a specific distance within a given amount of time. This calculation takes into account the remaining distance to be traveled and the remaining time available.

How is "speed for remaining time and distance" calculated?

The formula for calculating speed for remaining time and distance is: Speed = Remaining Distance / Remaining Time. This calculation can be applied to any unit of distance and time as long as they are consistent.

What is the importance of "speed for remaining time and distance"?

Knowing the speed required to reach a specific distance within a given time frame is important for various scientific and practical applications. It can be used in transportation planning, sports training, and even in space exploration to determine the necessary velocity for a spacecraft to reach its destination within a specified time.

How is "speed for remaining time and distance" different from average speed?

While average speed is calculated by dividing the total distance traveled by the total time taken, "speed for remaining time and distance" takes into account the remaining distance and time available. This means that it can provide a more accurate estimate of the velocity needed to reach a specific distance within a given time frame.

Can "speed for remaining time and distance" be applied to non-linear motion?

Yes, "speed for remaining time and distance" can be applied to both linear and non-linear motion. However, in cases of non-linear motion, the calculation becomes more complex and may require additional variables to be considered such as acceleration and deceleration.

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