A steel ball of mass 1.07 kg is attached to a thin (massless) cable and whirled around in a circle in a vertical plane. The circle has a radius of 1.38 m. When it is at the bottom of the circle, the ball has a speed of 13.9 m/s. Calculate the magnitude of the tension in the cable when the mass is at the bottom of the circle. (in N)

160.296 N

Explanation:

At the bottom of the circle,

Applying,

Tension  = centrifugal force- weight  of the ball

T = mv²/r-mg Equation 1

Where T = tension in the cable, m = mass of the ball, v = speed of the ball, r = radius of the circle, g = acceleration due to gravity

Given: m = 1.07 kg, v = 13.9 m/s, r = 1.38 m, g = 9.8 m/s²

Substitute into equation 1

T = (1.07(13.9²)/1.38)+[1.07(9.8)]

T = (1.07(193.21)/1.38)+(10.486)

T = (206.7347/1.38)+(10.486)

T = 149.81+10.486

T =160.296 N

Hence the tension in the cable when the mass is at the bottom of the circle = 160.296 N

when heated, the valance electrons increased their speed and transferred the heat from electron to electron.   i just took the test.

96.77 amp

explanation:

rl = 250/100 = 2.5 ohms.

egl = 250 + (100 × 0.1) + 2 = 262 v.

at 700 r.p.m., eg2 = 262 × 700/1000 = 183.4 v.

if ia is the new current, then eg2 - 2 - (ia × 0.1) = 2.5 ia

which means this will give ia = 96.77 amp.