What is the change in internal energy if 30 j of thermal energy is released
from a system, and the system does 40 j of work on the surroundings? use a
u= q-w.

ΔU = -70 J

Explanation:

ΔU = Q − W

where ΔU is the change in internal energy,

Q is the heat absorbed by the system,

and W is the work done by the system (on the surroundings).

30 J of thermal energy is released, so Q = -30 J.

40 J of work is done by the system, so W = 40 J.

Therefore, the change in internal energy is:

ΔU = -30 J − 40 J

ΔU = -70 J

dec 23, 2016 - a load of bricks weighing 680 n a distance of 10 m across a parking lot. if if the worker pushes the cart with a constant force of 209 n, what work= force x distance = 220 n x 10 m = 2200 n.m = 2200 j i don't know where the person got it from, but the initial part, work= force x distance me.