Vs - velocity on beginning
ve - velocity on ending. You've got:

So he needed 4 second.
Answer:
9 kW-hr
Explanation:
3000 W = 3 kW for 1 hr = <u>3 kW - hr </u>
2000 W = 2 kW for 3 hr = <u> 6 kW -hr</u>
<u />
total power = <u> 3 + 6 = 9 kW-hr</u>
The maximum frictional force in the knee joint of a person who supports 76. 0 kg of her mass on that knee 119.28N.
Given,
m=76kg, μ=0.16, g=9.81 m/
frictional force = mμg= 76*0.16*9.81= 119.28 N
<h3>Frictional force</h3>
An opposing force to the relative motion of two bodies in contact is known as frictional force. Always acting in the opposite direction from the direction of motion, frictional force is applied to a moving body. Because it resists motion, it aids in lowering the moving object's speed. The force is one of touch. Four broad categories can be made for the force of friction depending on the sort of motion that occurs between the two objects. Static friction is the force of friction between an object and the surface it is put on.
What is the maximum frictional force in the knee joint of a person who supports 76. 0 kg of her mass on that knee?
Learn more about frictional force here:
brainly.com/question/13707283
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Answer:
N₁ = 393.96 N and N = 197.96 N
Explanation:
In This exercise we must use Newton's second law to find the normal force. Let's use two points the lowest and the highest of the loop
Lowest point, we write Newton's second law n for the y-axis
N -W = m a
where the acceleration is ccentripeta
a = v² / r
N = W + m v² / r
N = mg + mv² / r
we can use energy to find the speed at the bottom of the circle
starting point. Highest point where the ball is released
Em₀ = U = m g h
lowest point. Stop curl down
= K = ½ m v²
Emo = Em_{f}
m g h = ½ m v²
v² = 2 gh
we substitute
N = m (g + 2gh / r)
N = mg (1 + 2h / r)
let's calculate
N₁ = 5 9.8 (1 + 2 17.6 / 5)
N₁ = 393.96 N
headed up
we repeat the calculation in the longest part of the loop
-N -W = - m v₂² / r
N = m v₂² / r - W
N = m (v₂²/r - g)
we seek speed with the conservation of energy
Em₀ = U = m g h
final point. Top of circle with height 2r
= K + U = ½ m v₂² + mg (2r)
Em₀ = Em_{f}
mgh = ½ m v₂² + 2mgr
v₂² = 2 g (h-2r)
we substitute
N = m (2g (h-2r) / r - g)
N = mg (2 (h-r) / r 1) = mg (2h/r -2 -1)
N = mg (2h/r - 3)
N = 5 9.8 (2 17.6 / 5 -3)
N = 197.96 N
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