A semi-truck is going up a steep hill and its speed changes from 65 mi/hr to 40 mi/hr when it reaches the top in 8 minutes. What is the truck's acceleration? If the acceleration is negative, what is it called? SHOW YOUR WORK.

The boy of mass 30 kg is at r1= 2 meters from the fulcrum. of the girl is 45 kg, at what r2 must she sit so that they are balanced ?

Suppose a diode consists of a cylindrical cathode with a radius of 6.200×10^−2 cm , mounted coaxially within a cylindrical anode with a radius of 0.5580 cm . the potential difference between the anode and cathode is 260 v . an electron leaves the surface of the cathode with zero initial speed (v initial=0). find its speed vfinal when it strikes the anode.

The vapour pressure of benzene is 53.3 kpa at 60.6 °c, but it fell to 51.5 kpa when 19.0 g of a non-volatile organic compound was dissolved in 500 g of benzene. calculate the molar mass of the compound.