Answer:
Explanation:
charge transferred to sphere = 12 - 8 = 4 nC
a )
The positive charge is decreased on glass rod , that means electrons must have entered the glass rod from the sphere which reduces its positive charge.
b )
charge transferred = 4 nC = 4 x 10⁻⁹ C
charge on one electron = 1.6 x 10⁻¹⁹ C
No of electrons transferred
= Total charge transferred / charge on one electron
= 4 x 10⁻⁹ / 1.6 x 10⁻¹⁹
= 2.5 x 10¹⁰ .
Answer:
Positive work
Explanation:
When work and the exerted force are in the same direction, then the work done is positive.
In the question, we understand that Marvin lifts a box up (i.e. over his head). The force to lift the box acts in the upward direction and the work done itself is also in the upward direction (from the floor to Marvin's head).
Since these two are in the same direction, then we can conclude that the work done is positive.
Answer:
Bohr's Model
Explanation:
I took the test and got it right
Explanation:
Objects like apples, wood, and sponges are less dense than water. They will float. Many hollow things like empty bottles, balls, and balloons will also float. That's because air is less dense than water.
The correct answer to the question is 2.27 
i.e the acceleration of the body is 2.27 along the forward direction.
CALCULATION:
As per the question, the net external force on the propeller of model airplane F = 6.8 N.
The mass of the model air plane m = 3.0 kg
We are asked to calculate the acceleration of the air plane.
From Newton's second law of motion, we know that the net external force acting on a body is equal to the product of mass with acceleration of that body.
Mathematically force F = m × a
⇒ 
[ans]
The direction of acceleration is along the direction of force. Hence, the acceleration of the propeller is 2.27 along forward direction.
