The potential energy of a 40-kg cannonball is 14000 J. How high was the cannon ball to have this much potential energy?

The rigid beam is supported by the three suspender bars. bars ab and ef are made of aluminum and bar cd is made of steel. if each bar has a cross-sectional area of 450 mm2, determine the maximum value of p if the allowable stress is (σallow)st = 200 mpa for the steel and ( σallow)al = 150 mpa for the aluminum. est = 200 gpa and eal = 70 gpa.

Thomas his older brothers, who own a junk yard, on the weekends to earn extra money. he likes to them push broken-down cars to the back of the junk yard because it makes him feel strong. last saturday, they pushed three cars with different weights, and he noticed he used different amounts of force for each one. the cars were the following weights: white car: 2,700 kg red car: 1,500 kg blue car: 2,100 kg think about how much force is needed to move each car. which correctly lists the cars in order from the most to least amount of force needed to move them? a) white, blue, red b) blue, red, white c) red, white, blue d) white, red, blue

The ultracentrifuge is an important tool for separating and analyzing proteins. because of the enormous centripetal accelerations, the centrifuge must be carefully balanced, with each sample matched by a sample of identical mass on the opposite side. any difference in the masses of opposing samples creates a net force on the shaft of the rotor, potentially leading to a catastrophic failure of the apparatus. suppose a scientist makes a slight error in sample preparation and one sample has a mass 10 mg larger than the opposing sample. if the samples are 12 cm from the axis of the rotor and the ultracentrifuge spins at 70,000 rpm, what is the magnitude of the net force on the rotor due to the unbalanced samples? ( be thorough on your answer)