A61-kg acrobat must jump high and land on his brother's shoulders. to accomplish this, he leaps from a crouched position to a height where his center of mass is 1.20 m above the ground. his center of mass is 400 mm above the ground. part a: what is the average force exerted on him by the ground during the jump? part b: what is his maximum speed?

Aballet student who learns with the of his instructor is demonstrating learning.

Consider a uniformly charged ring in the xy plane, centered at the origin. the ring has radius a and positive charge qdistributed evenly along its circumference. a)what is the direction of the electric field at any point on the z axis? . b)what is the magnitude of the electric field along the positive z axis? use k in your answer, where k=14πϵ0. d)the ball will oscillate along the z axis between z=d and z=−d in simple harmonic motion. what will be the angular frequency ω of these oscillations? use the approximation d≪a to simplify your calculation; that is, assume that d2+a2≈a2. express your answer in terms of given charges, dimensions, and constants

The force it would take to accelerate an 900-kg car at the rate of 6m/s2