Answer:
7.07 hours
Explanation:
divide the distance by the speed
so in this case, divide 672 by 95
I attached the full question.
We know that for a parallel-plate capacitor the surface charge density is given by the following formula:

Where V is the voltage between the plates and d is separation.
Voltage is by definition:

Voltage is analog to the mechanical work done by the force.
Above formula is correct only If the field is constant, and we can assume that it is since no function has been given.
The charge density would then be:

Please note that elecric permittivity of air is very close to elecric permittivity of vacum, it is common to use them <span>interchangeably</span>.
Answer:
The toy's energy is 18 J.
Explanation:
We have, a 4 kg toy is lifted off the ground and falls at 3 m/s. It is required to find toy's energy.
The toy will have kinetic energy due to its motion. The energy is given by :

So, the toy's energy is 18 J.
Answer:
It would take the object 5.4 s to reach the ground.
Explanation:
Hi there!
The equation of the height of a free-falling object at any given time, neglecting air resistance, is the following:
h = h0 + v0 · t + 1/2 · g · t²
Where:
h = height of the object at time t.
h0 = initial height.
v0 = initial velocity.
g = acceleration due to gravity (-32.2 ft/s² considering the upward direction as positive).
t = time
Let´s supose that the object is dropped and not thrown so that v0 = 0. Then:
h = h0 + 1/2 · g · t²
We have to find the time at which h = 0:
0 = 470 ft - 1/2 · 32.2 ft/s² · t²
Solving for t:
-470 ft = -16.1 ft/s² · t²
-470 ft / -16.1 ft/s² = t²
t = 5.4 s
Answer:
the force of friction = fk = (uk)n = 402(uk)
the net force acting to accelerate bookcase = ma = (41)(0.12) = 4.9 N
the {assumed horizontal} push force = 65 N
so
65 - fk = 4.9
fk = 65 - 4.9 = 60 N
uk = 60/402 = 0.15 <= ANS