A car travelled 60 km west in 1.33 h along straigt line , then returned back east for 40 km in 0.67 h . its average velocity

7.29 km/h East

Explanation:

Velocity is distance covered per unit time, with consideration to the direction.

Taking East as positive then West is negative

Velocity when traveling towards West

V=d/t where d is distance and t is time taken. Substituting 60 km dor d and 1.33 for t then

V=-60/1.33=-45.112781954887 km/h West

Velocity when traveling towards East

V=d/t where d is distance and t is time taken. Substituting 40 km dor d and 0.67 for t then

V=40/0.67=59.701492537313 km/h East

Average velocity=(velocity East+West)/2

Average velocity is (59.701492537313+-45.112781954887)/2=7.29 km/h

Since the average is positive, then the direction is East

Therefore, the average velocity is 7.29 km/h East

3.2x10^7

96.77 amp

explanation:

rl = 250/100 = 2.5 ohms.

egl = 250 + (100 × 0.1) + 2 = 262 v.

at 700 r.p.m., eg2 = 262 × 700/1000 = 183.4 v.

if ia is the new current, then eg2 - 2 - (ia × 0.1) = 2.5 ia

which means this will give ia = 96.77 amp.