A hot-air balloon contains air at a temperature of 180 oF. The surrounding air has a temperature of 60 oF. The radius of the spherical balloon is 30.6 ft. The weight of the empty balloon is 200lb. Determine the maximum load (in lbf) that the balloon can lift. Use thermodynamic tables to obtain the density of the hot-air and surrounding air.

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.

Crowbar of 5 metre is used to lift an object of 800 metre if the effort arm is 200cm calculate the force applied

What are atoms of the same element with varying number of neutrons