An astronaut in an inertial reference frame measures a time interval Δt between her heartbeats. What will observers in all other inertial reference fr

It will be more than deta t

Explanation:

Because

deta t' = န deta t

But န= 1/√ (1 - v²/c²

So the observers in all the initial frames will be more than deta t

b.a device that inputs heat into a cool object

d₁ = displacement of tern from arctic to antarctic = 11000 miles

d₂ = displacement of tern from antarctic to arctic =   - 11000 miles

d = total displacement for the journey

total displacement for the journey is given as

d = d₁ + d₂

d = 11000 + (-11000)

d = 0 miles

t₁ = time of travel from arctic to antarctic = 3 months = 3 x 30 days = 90 days

t₂ = time of travel from antarctic to arctic = 3 months = 3 x 30 days = 90 days

t = total time of travel

total time of travel is given as

t = t₁ + t₂

t = 90 + 90

t = 180 days

average velocity is given as

average velocity = total displacement/ total time

v = d/t

v = 0/180

v = 0 miles/day