Help please!
What are the answers
From 4 to 8?

Name two kinds of practical electric pumps.

Ahot-air balloon takes off from the ground traveling vertically with a constant upward acceleration of magnitude g/4. after time interval δt, a crew member releases a ballast sandbag from the basket attached to the balloon. how many seconds does it take the sandbag to reach the ground? (express your answer in terms of δt)

Which describes increasing the efficiency of energy resource