You drive on interstate 10 from san antonio to houston, half the time at 51 km/h and the other half at 71 km/h. on the way back you travel half the distance at 51 km/h and the other half at 71 km/h.
what is your average speed (a) from san antonio to houston, (b) from houston back to san antonio, and (c) for the entire trip? (d) what is your average velocity for the entire trip?

Part a)

Part b)

Part c)

Part d)

average velocity must be ZERO

Explanation:

While he drive San Antonio to Houston

Half the time move with speed 51 km/h and next half his speed is 71 km/h

so we have

so average speed is given as

Part b)

While he move from Houston to San Antonio half the distance is moved with 51 km/h and next half distance with 71 km/h

so we have

so average speed is given as

Part c)

Average speed for entire trip

Part d)

Since total displacement of entire trip is zero

so average velocity must be ZERO

continuous conducting path for current, power supply

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min