Answer:
I think the answer is B, I am not for sure
Thermal energy is the total energy of all the molecules in an object. The thermal energy of an object depends on three things: 4 the number of molecules in the object 4 the temperature of the object (average molecular motion) 4 the arrangement of the object's molecules (states of matter).
Hope this helps
The box is kept in motion at constant velocity by a force of F=99 N. Constant velocity means there is no acceleration, so the resultant of the forces acting on the box is zero. Apart from the force F pushing the box, there is only another force acting on it in the horizontal direction: the frictional force
which acts in the opposite direction of the motion, so in the opposite direction of F.
Therefore, since the resultant of the two forces must be zero,
so
The frictional force can be rewritten as
where
,
. Re-arranging, we can solve this equation to find
, the coefficient of dynamic friction:
Answer:
A. Wab > 0.
Explanation:
Work done will be equal to change in gravitational energy in the whole process .
When Masses M₁ and M₂ are initially separated by a distance Ra
their gravitational energy
= - G M₁ M₂ / Ra
When mass M₂ is now moved further away from mass M₁ such that their final separation is Rb
their gravitational energy
= - G M₁ M₂ / Rb
Change in gravitational energy
= - G M₁ M₂ / Rb - ( - G M₁ M₂ / Ra )
= G M₁ M₂ / Ra - - G M₁ M₂ / Rb
= G M₁ M₂ ( 1 / Ra - Rb )
As Ra < Rb
1/Ra > 1 / Rb
So change in gravitational energy is positive
So
Wab > 0.
Answer:
Explanation:
a ) gauge pressure will be due to water column of length 15 cm .
pressure = h d g , h is height of column , d is density of column and g is gravitational acceleration .
= .15 x 10³ x 9.8
= 1470 Pa .
b )
Let due of weight of water column , mercury level in left column goes down by distance h . The level of mercury in right column will rise by the same distance ie by distance h .
So mercury column of 2h height is balancing the water column of height 15 cm
2h x 13.6 x 10³ x g = .15 x 10³ x g
h = .15 / (2 x 13.6)
= .55 x 10⁻² m
= . 55 cm
Difference of height of water column and mercury column
= 15 - 2 x .55 cm
= 13.9 cm .
