My notes as the initially empty urinary bladder fills with urine and expands, its internal pressure increases by 3300 pa, which triggers the micturition reflex (the feeling of the need to urinate). the drawing shows a horizontal, square section of the bladder wall with an edge length of 0.01 m. because the bladder is stretched, four tension forces of equal magnitude t act on the square section, one at each edge, and each force is directed at an angle θ below the horizontal. what is the magnitude t of the tension force acting on one edge of the section when the internal bladder pressure is 3300 pa and each of the four tension forces is directed 5.0° below the horizontal

       T = 0.946 N

Explanation:

there are four tension forces making an angle θ where θ = 5.0

side of the length l = 0.01 m

Area A = 0.01 * 0.01 m

             = 1.0*10^-4 m^2

Pressure inside the bladder is P = 3300 Pa

            ( 3300 Pa ) ( 1.0*10^-4 m^2   = 4 T sin (5.0 )

            T = 0.946 N

the current is 0.6

voltage ÷ resistance = current

so 12 ÷ 20 = 0.6

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.