If the above box was lifted in 3s, what was the power used? A car has a mass of 20,000kg. How much energy would be needed to lift the car 5m?
You apply a force of 3,000N to the lever of the jack. The car rises 0.25m. The lever on the jack goes down 3.2m. What is the force on the car?

What happens to the light rays when they hit the specimen?

In positive numbers less than 1, the zeros between the decimal point and a non-zero number are blank significant

Consider a 1000 w iron whose base plate is made of 0.5 cm thick aluminum alloy 2024-t6 (ρ = 2770 kg/m3 and cp = 875 j/kg°c). the base plate has a surface area of 0.03 m2. initially, the iron is in thermal equilibrium with the ambient air at 22°c. assuming 90% of the heat generated in the resistance wires is transferred to the plate, determine the minimum time needed for the plate temperature to reach 200°c.