A train is accelerating at a rate of 4.0 km/hr/s. If it's initial velocity is 40km/hr, what is its velocity after 30 seconds

i had this question and the answer was 3.15 miles.

martina travels from school to her mom's office. from there, she walks to school. after school, she walks to the library and then to a friends house before finally ending back at home. find martina's total distance traveled.

a) 0 miles  

b) 0.4 miles  

c) 1 mile  

d) 3.15 miles

answer is slate

hope this