Answer:
Explanation:
mass, m = 1 kg
Position (2, 3 ) m
height, h = 2 m
acceleration due to gravity, g = 9.8 m/s^2
Here, no force is acting in horizontal direction, the force of gravity is acting in vertical direction, so the work done by the gravitational force is to be calculated.
Force mass x acceleration due to gravity
F = 1 x 9.8 = 9.8 N
Work = force x displacement x CosФ
Where, Ф be the angle between force vector and the displacement vector.
Here the value of Ф is 180° as the force acting vertically downward and the displacement is upward
So, W = 9.8 x 2 x Cos 180°
W = - 19.6 J
Thus, option (A) is correct.
Answer:
a) C = 4,012 10⁻¹⁴ F, b) Q = 1.6 10⁻¹¹ C
, c) U = 3.21 10⁻¹¹ J
Explanation:
a) The capacitance of a capacitor is
C = k e₀ A / d
Let's calculate
C = 4 8.85 10⁻¹² 17 10⁻⁴ / 0.150 10⁻²
C = 4,012 10⁻¹⁴ F
b) let's look the charge
C = Q / ΔV
Q = C ΔV
Q = 4,012 10⁻¹⁴ 400
Q = 1.6 10⁻¹¹ C
c) The stored energy
U = ½ C ΔV²
U = ½ 4,012 10⁻¹⁴ 400²
U = 3.21 10⁻¹¹ J
When you heat something of cool it down you don't change the substance you might change the why is looks, but it is still the same substance. For example you cool water to 0 degrees Celsius it turns into ice but it still is two parts hydrogen and one part oxygen H2O. Physical changes will change state and/or form but it will still be what it originally was on the molecular level. Hope that helped.
The correct answer is Mechanics
