Two pole-vaulters just clear the bar at the same height. the first lands at a speed of 8.27 m/s, while the second lands at a speed of 8.71 m/s. the first vaulter clears the bar at a speed of 0.742 m/s. ignore air resistance and friction and determine the speed at which the second vaulter clears the bar.

2.83227 m/s

Explanation:

K = Kinetic energy

P = Potential energy

v = Final velocity

u = Initial velocity

g = Acceleration due to gravity = 9.81 m/s²

h = Height of the bar

Here the energies of the system are conserved

The same can be applied to the second pole vaulter

The speed at which the second vaulter clears the bar is 2.83227 m/s

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.