Answer:
Thomson's model showed an atom that had a positively charged medium, or space, with negatively charged electrons inside the medium. After its proposal, the model was called a "plum pudding" model because the positive medium was like a pudding, with electrons, or plums, inside.
Answer:
Force = 125 [N]
Explanation:
In the attached image we can see a sketch of the lever system.
And if we make a sum of moments at the point O equal to zero (0).
In the equation showed in the image, we can determinate the force that we need
Answer:
B. 161.5 J
Explanation:
= Number of moles = 0.37
= Rise in the temperature of the oxygen gas = 15 K
= heat added in order to raise the temperature
= specific heat at constant pressure = 3.5
At constant pressure, heat is given as

Answer:
Explanation:
Calories to be burnt = 3500 - 2500 = 1000 Cals .
Efficiency of conversion to mechanical work is 25 % .
Work needed to burn this much of Cals = 1000 x 100 / 25 = 4000 Cals.
4000 Cals = 4.2 x 4000 = 16800 J .
Work done in one jump = kinetic energy while jumping
= 1/2 m v²
= .5 x 70 x 3.3²
= 381.15 J .
Number of jumps required = 16800 / 381.15
= 44 .