Question

A train goes from springfield, MA, to boston at 40 mph. On the way back, it returns with a speed 80 mph. If it takes an hour less time to return, what is it's average speed?

Answer 1

The average speed for the entire journey will be 53.333 miles per hour.

What is the average speed?

The average speed is the ratio of the total distance traveled to the total time taken by the body. Its unit is m/sec.

The distance from the Springfield, MA, to Boston is, L

v₁ is the velocity during traveling from Boston to Springfield, MA

v₂ is the  velocity during traveling from Springfield, MA to Boston

t₁ is the time needed to travel from Boston to Springfield, MA

t₂ is the time needed to travel from Springfield, MA to Boston

t is the total time period of the journey

v is the average speed

From the formula of distance;

Distance = speed × time

The speed of train for the going from Springfield, MA, to Boston is 40 mph. The time period is calculated as;

L = v₁ × t₁

t₁ = L/v₁

t₁ = L/40

The speed of train for the going from Boston to Springfield, MA, is 80 mph. The time period is calculated as;

L = v₂ × t₂

t₂ = L/v₂

t₂ = L/80

The total time is taken;

t = t₁ + t₂

t =  (L/40)+( L/80)

t=3L/80

The ratio of total distance traveled to the total time spent by the body is known as average speed, calculated as;

Average speed = Total distance / Total time

v = 2L / (3L/80)

v= (2L × 80)/3L

v = 160 / 3

v = 53.333 miles per hour.

Hence the average speed for the entire journey will be 53.333 miles per hour.

To learn more about the average speed, refer to the link;

brainly.com/question/12322912

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