Answer:
a) 7200 ft/s²
b) 140 ft
c) 3.7 s
Explanation:
(a) Average acceleration is the change in velocity over change in time.
a_avg = Δv / Δt
We need to find what velocity the puck reached after it was hit by the hockey player.
We know it reached 40 ft/s after traveling 90 feet over rough ice at an acceleration of -20 ft/s². Therefore:
v² = v₀² + 2a(x − x₀)
(40 ft/s)² = v₀² + 2(-20 ft/s²)(100 ft − 10 ft)
v₀² = 5200 ft²/s²
v₀ = 20√13 ft/s
So the average acceleration impacted to the puck as it is struck is:
a_avg = (20√13 ft/s − 0 ft/s) / (0.01 s)
a_avg = 2000√13 ft/s²
a_avg ≈ 7200 ft/s²
(b) The distance the puck travels before stopping is:
v² = v₀² + 2a(x − x₀)
(0 ft/s)² = (5200 ft²/s²) + 2(-20 ft/s²)(x − 10 ft)
x = 140 ft
(c) The time the puck takes to travel 10 ft without friction is:
t = (10 ft) / (20√13 ft/s)
t = (√13)/26 s
The time the puck travels over the rough ice is:
v = at + v₀
(0 ft/s) = (-20 ft/s²) t + (20√13 ft/s)
t = √13 s
So the total time is:
t = (√13)/26 s + √13 s
t = (27√13)/26 s
t ≈ 3.7 s
Answer:
(a): It spends on the trip 2.75 hr (2 hours 45 minutes)
(b): The person travels 213.9 km.
Explanation:
Vp= 77.8 km/h
V1= 89.5 km/h
V2= 0 km/h
t2= 0.36hr
t1= ?
Vp= (V1*t1 + V2*t2) / (t1 + t2)
clearing t1:
t1= 2.39 hr
Trip time= t1+t2
Trip time= 2.75 hr (a)
Distance traveled= V1*t1
Distace traveled= 213.9 km (b)
Rational expectations theory suggests that the speed of adjustment Purcell correction would be very quick.
<h3>What Is Rational Expectations Theory?</h3>
The rational expectations theory is a widely used concept and modeling technique in macroeconomics. Individuals make decisions based on three primary factors, according to the theory: their human rationality, the information available to them, and their past experiences.
The rational expectations hypothesis was originally suggested by John (Jack) Muth 1 (1961) to explain how the outcome of a given economic phenomena depends to a certain degree on what agents expect to happen.
- People who have rational expectations always learn from their mistakes.
- Forecasts are unbiased, and people make decisions based on all available information and economic theories.
- People understand how the economy works and how government policies affect macroeconomic variables like the price level, unemployment rate, and aggregate output.
To learn more about Rational expectations theory from the given link
brainly.com/question/16479910
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Answer:
(A) She needs to move the decimal point by 3 places
