Answer:
The change in the charge on the positve plate when the Teflon is inserted is +2.5 nC.
Explanation:
- It can be showed that the capacitance of a parallel-plate capacitor, can be expresssed as follows:
- Where ε, is the dielectric constant of the material that fills the space between plates.
- When this space is filled with air, ε= ε₀ = 8,85*10⁻¹² F/m.
- At the same time, the capacitance of a capacitor, by definition, is as follows:
- If we insert a Teflon slab, in such a way that fills completely the gap between the plates, all other parameters being equal, if ε = 2*ε₀, this means that C₂ = 2* C₁. = 50 pF
- As V₂=V₁ (due to the capacitor remains connected to the same battery) the charge must be the double, so Q₂ = 2* Q₁ = 5 nC.
- So, the change in the charge of the positive plate is +2.5 nC.
Answer:
Explanation:
Density = Mass / Volume = 850 / 40*10*5 = 0.425 g /cm^3
Answer:
the velocity is zero, the acceleration is directed downward, and the force of gravity acting on the ball is directed downward
Explanation:
Is this exercise in kinematics
v = v₀ - g t
where g is the acceleration of the ball, which is created by the attraction of the ball to the Earth.
At the highest point
velocity must be zero.
The acceleration depends on the Earth therefore it is constant at this point and with a downward direction.
The force of the earth on the ball is towards the center of the Earth, that is, down
all other alternatives are wrong
Answer:
180 m
Explanation:
The rock follows a free-fall motion - so the vertical distance covered can be found by using the equation
where
g = 10 m/s^2 is the acceleration due to gravity
t = 6.00 s is the time of the fall
Substituting these data, we find the height of the cliff:
Answer:
24kgm/s
Explanation:
Given parameters:
Force = 80N
Mass of object = 6kg
Initial velocity = 4m/s
Final velocity = 8m/s
Solution:
Impulse = ?
Solution:
The impulse on a body is its change in momentum.
Impulse = m (v - u )
m is the mass
v is the final velocity
u is the initial velocity
Now insert the parameters and solve;
Impulse = 6 (8 - 4) = 24kgm/s
