Answer:
the resulting angular acceleration is 15.65 rad/s²
Explanation:
Given the data in the question;
force generated in the patellar tendon F = 400 N
patellar tendon attaches to the tibia at a 20° angle 3 cm( 0.03 m ) from the axis of rotation at the knee.
so Torque produced by the knee will be;
T = F × d⊥
T = 400 N × 0.03 m × sin( 20° )
T = 400 N × 0.03 m × 0.342
T = 4.104 N.m
Now, we determine the moment of inertia of the knee
I = mk²
given that; the lower leg and foot have a combined mass of 4.2kg and a given radius of gyration of 25 cm ( 0.25 m )
we substitute
I = 4.2 kg × ( 0.25 m )²
I = 4.2 kg × 0.0626 m²
I = 0.2625 kg.m²
So from the relation of Moment of inertia, Torque and angular acceleration;
T = I∝
we make angular acceleration ∝, subject of the formula
∝ = T / I
we substitute
∝ = 4.104 / 0.2625
∝ = 15.65 rad/s²
Therefore, the resulting angular acceleration is 15.65 rad/s²
Answer:
0.144 kg of water
Explanation:
From Raoult's law,
Mole fraction of solvent = vapor pressure of solution ÷ vapor pressure of solvent = 423 mmHg ÷ 528.8 mmHg = 0.8
Let the moles of solvent (water) be y
Moles of solute (C3H8O3) = 2 mole
Total moles of solution = moles of solvent + moles of solute = (y + 2) mol
Mole fraction of solvent = moles of solvent/total moles of solution
0.8 = y/(y + 2)
y = 0.8(y + 2)
y = 0.8y + 1.6
y - 0.8y = 1.6
0.2y = 1.6
y = 1.6/0.2 = 8
Moles of solvent (water) = 8 mol
Mass of water = moles of water × MW = 8 mol × 18 g/mol = 144 g = 144/1000 = 0.144 kg
Answer:

Explanation:
In series combination, the equivalent resistance is given by :

Let the identical resistors be R. We have, 
So,

So, the resistance of each resistor is
.
We will apply the concept of period in a pendulum, defined as the product between 2
by the square root of the length over gravity, this is mathematically

Here,
T = Period
L = Length
g = Acceleration due to gravity
For the period to be 1 second, then we must look for the necessary length for such a requirement so




The meter's length would be slight less than one-fourth of its current length. Also, the number of significant digits depends only on how precisely we know g, because the time has been defined to be exactly 1s.
Therefore the correct answer is C.