The reading on the scale is the tension on the string that connects the two objecst. In order to support the blocks it must pull the weights by a force magnitude of W. So, the tension of the rope is W. Therefore, the reading on the scale is W, D.
I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!
The ducks speed is 10m per second
Answer:

Explanation:
As we know that
PV = nRT
here we have


so we have

T = 290 K
now we have


now the mass of gas is given as



now density of gas when its volume is increased to 3.3 L
so we will have



The efficiency of the device is 30 %
Explanation:
The efficiency of a heat engine is given by:

where
W is the work done by the engine
is the heat in input to the engine
For the device in this problem, we have:
W = 120 J is the work done
is the heat in input
Substituting, we find the efficiency:

which corresponds to an efficiency of 30%.
Learn more about work:
brainly.com/question/6763771
brainly.com/question/6443626
#LearnwithBrainly