Since acceleration = Vf- Vi/t
Vf = 75m/s
Vi = 30m/s
Then acceleration = 75-30/5
= 9m/s.
We have: Power = Force × Displacement/Time
Here, Force = 300 N
Displacement = 24.4 m
Time = 15 s
Substitute their values in the formula:
P = 300 × 24.4/15
P = 20 × 24.4
P = 488
Finally, Option B is your final answer.
Hope this helps!!
Answer:
fr = m v₀² / 2 (x₁-x₀)
Explanation:
a) For this exercise we use Newton's second law
X axis
- fr = ma
Y Axis
N-W = 0
N=W
let's look for acceleration with expressions of kinematics
v² = v₀² - 2 a Δx
at the point where stop v = 0
a = v₀² / 2 Δx
let's replace
-fr = m (- v₀² / 2 (x₁-x₀))
fr = m v₀² / 2 (x₁-x₀)
b)they ask for the same
in this case part of rest
v₁² = 0 + 2 a Δx
a = v₁² / 2ΔX
we write Newton's second law
F - fr = m a
fr = F - ma
fr = F - m v₁² / 2Δx
