Answer:
24 cm
Step-by-step explanation:
Given that:
Rate at which coastline recedes per year = 3cm
Recede rate occurred uninterrupted for 8 years ; how far will the coastline recede in 8 years :
3cm per year for 8 years
Hence,
3cm * 8
= 24 cm
The coastline would have recede for 24cm in 8 years
It wont open it up, so no one can really help
Answer:
14hrs
Step-by-step explanation:
v = speed in still water
t = downstream trip time
d = distance = 182 miles; same distance both downstream and upstream
t + 12 = upstream return trip time
u = current flow = 3 mph
Downstream: d = (v + u)t; Upstream: d = (v - u)(t + 12)
(v - 3)(t + 12) = 182 (equation 1)
(v + 3)t = 182 (equation 2)
Subtract equation 2 from equation 1 to get t:
(vt + 12v -3t -36) - (vt + 3t) = 0
12v - 6t - 36 = 0
t = 2v - 6
Substitute this result for t into equation 2 and solve for v:
(v + 3)(2v - 6) = 182
2v^2 - 6v + 6v - 18 = 182
v^2 = 100
v = 10 mph
t = 2v - 6 = [2(10) - 6] hrs = 14 hrs
Answer:
When you are calculating the amount of mechanical energy used to exert force and move something, you are talking about work being done by a force at a distance. You can describe this in terms of foot-pounds. For example, you want to calculate the energy used to tighten a nut when using a wrench, or to lift a weight from the floor. Mechanical force takes place in time, so to describe the power requirement, you use foot-pounds per second.
Step-by-step explanation:
