Answer:
r = 0.119 m
Explanation:
distance (d) = 1.6 mm = 0.0016 m
electric field strength (E) = 2.7 x 10^{6} N/C
charge (Q) = -1.07 μC = -1.07 x 10^{-6} C
permitivity of vacuum = 8.8542 x 10^{-12} C^{2}/N
find the radius of the plate required
- lets first find the voltage
voltage (V) = E x d
voltage (V) = 2.7 x 10^{6} x 0.0016 = 4320 V
- lets also find capacitance (C) = Q/V
C = -1.07 x 10^{-6} / 4320 = 2.47 x 10^{-10} F
- the value of capacitance (C) is also = E₀A / d
we can rearrange the equation above to have our area (A) = Cd/ E₀
A =
A = 0.0446 m^{2}
- Area (A) = π x
r =
r =
r = 0.119 m
Answer:
Option D - 0.2 s
Explanation:
We are given;
Initial velocity; u = 7 m/s
Height of table; h = 1.8m
Now,since we want to find the time the car spent in the air, we will simply use one of Newton's equation of motion.
Thus;
h = ut + ½gt²
Plugging in the relevant values, we have;
1.8 = 7t + ½(9.8)t²
4.9t² + 7t - 1.8 = 0
Using quadratic formula to find the roots of the equation gives us;
t = -1.65 or 0.22
We can't have negative t value, thus we will pick the positive one.
So, t = 0.22 s
This is approximately 0.2 s
The answer to this question is Gravity
Use SUVAT where:
S = distance
U = initial velocity = 30m/s
V = end velocity = 0 m/s
A = acceleration = ?
T = time = 5 secs
then pick out the equation v = u + at
so:
0 = 30 + 5a
-30 / 5 = a
a = -6 m/s^2
At its highest point (Point A) the pendulum is momentarily motionless. All of the energy in the pendulum is gravitational potential energy and there is no kinetic energy. At the lowest point (Point D) the pendulum has its greatest speed. All of the energy in the pendulum is kinetic energy and there is no gravitational potential energy