Answer:
Q=+100kj,w=-15kj,Q=100kj,w=-62kj
Explanation:
when energy is exerted into a system work done is equal to zero .hence the system does work to the surrounding.
 
        
                    
             
        
        
        
There are approximately two hundred and twenty-five point seven five calories from using 945 j of heat
A: 225.75
        
             
        
        
        
Answer:
140 watt
Explanation:
We are given that
Force applied by student ,F=28 N
Weight pulled  by students=70 N
Displacement,s=15 m
Time=3 s
We have to find the power developed  by the student.
Work done=w=
Work done by the student=
Power=
Using the formula 
Power=
Hence, the power developed by the students=140 watt
 
        
             
        
        
        
Answer: work Melvin did=9000J
Explanation:
Given to complete the question: If the sled moved 33.9m,how much work did Melvin do? Answer in unit of J and round to the nearest thousandth.
W = F ×S
W = 317 × cos 33°×33.9
W=9012.6055J
W=9000J to the nearest thousandth