You drive on interstate 10 from san antonio to houston, half the time at 76 km/h and the other half at 119 km/h. on the way back you travel half the distance at 76 km/h and the other half at 119 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?

(a) 97.5km/h

(b) 97.5km/h

(c) 97.5km/h

(d) 0km/h

Explanation:

Speed and velocity concepts: Velocity is a vector, but speed does not have a direction. Speed is a scalar quantity, it is the magnitude of the velocity.

What is the speed for:

(a) from San Antonio to Houston: Average speed=(76+119)/2=97.5km/h

(b) from Houston back to San Antonio: Average speed=(76+119)/2=97.5km/h

(c) for the entire trip? : Average is the average between  (a) and (b), Average speed=97.5km/h

(d) What is your average velocity for the entire trip?

Velocity is the total distance divided the total time. For the entire trip the point of departure is the same at the point of arrival (San Antonio), so the vector distance travelled is zero, then the velocity for the entire trip is 0km/h

c) up is the direction the magnetic force is acting on the charge.