Answer:a
Explanation:
We have to lift the load two loads up one story, so energy required is
let m be the mass of each load and h is the height of each story
Energy 
Here energy gained is the potential energy which depends upon the datum(floor).
For lifting one load up one story
Energy required
thus 
is half of 
So option a is correct
Hi there!
Normal rain has a pH between 5.0 and 5.5, which is slightly acidic on the pH scale. Acid rain on the other hand has an average pH of 4.0, much more acidic than your average rain.
Therefore, the most likely pH of acid rain would be 4.0.
How can I help? What’s the question?
Answer:
1. be the first line of treatment for minor health conditions
2.be the first line of assessment and decision making for further diagnosis and/or treatment and for referral to a higher level facility
3. be a center for all public health activities, such as outreach ...
4. provide basic health services to people who live in rural areas.
