Speed physics homework

1. Jan 22, 2009

ViralRiver

1. The problem statement, all variables and given/known data
Can you help me answer this question?

Paolo and some friends want to order a take away. Paolo writes down what they need to know about the two nearest takeaways:

Ludo's Pizza:
Time to cook food is 1/4 hour
Distance to the house is 6.5 KM
Deliver on scooters with average speed of 30km/h

Moonlight Indian Takeaway:
Time taken to cook food is 1/2 hour
Distance to house is 4km
Delivery van has average speed of 40km/h

Which takeaway should they order from to get their food quickest? (please show working)

2. Relevant equations
s=d/t

3. The attempt at a solution
I've tried converting each variable to metres and minutes but I couldn't work it out.

Last edited by a moderator: Mar 7, 2013
2. Jan 22, 2009

Staff: Mentor

Re: Speed

Calculate time required to deliver the pizza once it is ready.

3. Jan 22, 2009

rl.bhat

Re: Speed

Find the time taken by the scooter to cover 6.5 km and van to cover 4 km. Add to them the respective time of cooking.

4. Jan 22, 2009

ViralRiver

Re: Speed

Yeah, but how?

5. Jan 22, 2009

Staff: Mentor

Re: Speed

Imagine you are riding on the bike at 10 mph. You are 5 miles from home. How long will it take to get home?

6. Jan 22, 2009

Stratosphere

Re: Speed

The First one is faster from what i worked out. it takes << answer deleted by berkeman >>.

Last edited by a moderator: Jan 22, 2009
7. Jan 22, 2009

Re: Speed

You have the correct answer, first is faster, but I think the times you calculated are wrong

8. Jan 22, 2009

Staff: Mentor

Re: Speed

Stratosphere: nobody asked you to do ViralRiver homework.

9. Jan 22, 2009

Stratosphere

Re: Speed

I did T=r/d to calculate the time it takes for the moped to get to the house.

10. Jan 22, 2009

Re: Speed

Got confused there, thought Stratosphere had asked the question originally. ViralRiver already gave the relevent equation (s=d/t) you ( or ViralRiver really) need to rearrange that for t.

11. Jan 22, 2009

ViralRiver

Re: Speed

This is what I got:

Ludo - 0.47 hours (2dp)
Moonlight - 0.6 hours

Is this right?

12. Jan 22, 2009

Re: Speed

Looks OK