A 100-W lightbulb is placed in a cylinder equipped with a moveable piston. The lightbulb is turned on for 0.010 hour, and the assembly expands from an initial volume of 0.90 L to a final volume of 5.92 L against an external pressure of 1.0 atm. Use the wattage of the lightbulb and the time it is on to calculate ΔE in joules (assume that the cylinder and lightbulb assembly is the system and assume two significant figures). Calculate w and q.

joules

joules

Explanation:

Let us convert the time in hours into seconds

Change in internal energy

where E is the internal energy in Joules

p is the power in watts

and t is the time in seconds

Joules

Amount of work done by the system

where P is the pressure and V is the volume

Substituting the given values in above equation, we get -

liter-atmospheres

Work done in Joules

Joules

Substituting the given values we get -

Thus

joules

joules

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.