Answer:
(a)
(b)
Explanation:
Let us take the north direction to be the positive y-axis and the east to be positive x-axis.
First day:
25.0 km southeast, which implies south of east. The y-component will be negative and the x-component will be positive.
Second day:
She starts off at the stopping point of last day. This time, both the y- and x-components are positive.
Therefore, total displacements:
Magnitude of displacements,
Direction,
Answer:
the charge per unit area on the plastic sheet is - 3.23 x 10⁻⁷ C/m²
Explanation:
given information:
styrofoam mass, m = 16 g = 0.016 kg
net charge, q = - 8.6 μC
to calculate the charge per unit area on the plastic sheet, we can use the following equation:
where
the force between the electric field
m = mass
g = gravitational force
where
q = charge
E = electric field
and
E = σ/2ε₀
where
ε₀ = permitivity
thus
mg = qσ/2ε₀
σ = (2mg ε₀)/q
= 2 (0.016) (9.8) (8.85 x 10⁻¹²)/( - 8.6 x 10⁻⁶)
= - 3.23 x 10⁻⁷ C/m²
Answer:
Approximately , assuming that the acceleration of this ball is constant during the descent.
Explanation:
Assume that the acceleration of this ball, , is constant during the entire descent.
Let denote the displacement of this ball and let
denote the duration of the descent. The SUVAT equation
would apply.
Rearrange this equation to find an expression for the acceleration, , of this ball:
.
Note that and
in this question. Thus:
.
Let denote the mass of this ball. By Newton's Second Law of Motion, if the acceleration of this ball is
, the net external force on this ball would be
.
Since and
, the net external force on this ball would be:
.