Question

You and your brother both leave your house at the same instant and drive in separate cars along a straight highway to a nearby lake. After 10 min, you are both 3.0 km from your house. You are now driving at 80 km/h , and you continue at this constant speed; your brother is going faster than this. After another 18 min , your brother arrives at the lake, but you are still 8.0 km away.

Part A) How far is it from your house to the lake?

Part B) What is your brother's average speed for the trip?

Part C) Your brother beats you to the lake by what time interval?

Image's bellow

ConstantsI Periodic Table You and your brother both leave your house at the same instant and drive in separate cars along a straight highway to a nearby lake. After 10 min, you are both 3.0 km from your house. You are now driving at 80 km/h , and you continue at this constant speed; your brother is going faster than this. After another 18 min , your brother arrives at the lake, but you are still 8.0 km away.

Answer 1

D = 3 + 18/60 times 80 + 8 = 3 + 24 + 8 = > d = 35 km V_avg = 35/(10 + 18/60) = 35 times 60/28 = > V_avg = 75 km/L Time taken by me, t_me = 10 + 18 + (8/80) times 60 = 10 + 18 + 6 = > t_me = 34 minute therefore Time interval = 34 min - 28 min = 6 minutes = 360 seconds