The speed is changing its direction all the time. There
is an acceleration which changes the direction of the speed – that is called
centripetal acceleration. Only uniform linear motions are considered to have no
acceleration.
This is the general formula for acceleration
a = dv/dt
When calculating dv, you should keep in mind the change
in the velocity vector’s direction. You can easily see in a graph that with dt
tending to 0 (so the length of the arc covered is also tending to 0), the difference
between vectors Vf and V0 has a direction which is perpendicular to velocity
(the shorter the arc, the closest the angle is to 90 degrees).
There is a formula (which can be deducted from the
previous formula) which allows you to calculate the acceleration:
a = v^2/r
Let’s talk about the units:
v is in m/s
r is in m
so v^2/r
is in (m/s)^2/m = (m^2/s^2)/m = m/s^2
which is the same unit as dv/dt:
dv/dt = (m/s)/s= m/s^2
satellite originally moves in a circular orbit of radius R around the Earth. Suppose it is moved into a circular orbit of radius 4R.
(i) What does the force exerted on the satellite then become?
eight times larger<span>four times larger </span>one-half as largeone-eighth as largeone-sixteenth as large(ii) What happens to the satellite's speed?<span>eight times larger<span>four times larger </span>one-half as largeone-eighth as largeone-sixteenth as large(iii) What happens to its period?<span>eight times larger<span>four times larger </span>one-half as largeone-eighth as largeone-sixteenth as large</span></span>
<span>
</span>
Answer:
U = (ε0AV^2) / 2d
Explanation:
Where C= capacitance of the capacitor
ε0= permittivity of free space
A= cross sectional area of plates
d= distance between the plates
V= potential difference
First, the capacitance of a capacitor is obtained by:
C = ε0A/d.
Starting at the formula , U= (CV^2)/2. Formula for energy stored in a capacitor
Substitute in for C:
U = (ε0A/d) * V^2 / 2
Hence:
U = (ε0AV^2) / 2d
Answer:
B can take 0.64 sec for the longest nap .
Explanation:
Given that,
Total distance = 350 m
Acceleration of A = 1.6 m/s²
Distance = 30 m
Acceleration of B = 2.0 m/s²
We need to calculate the time for A
Using equation of motion
Put the value in the equation
We need to calculate the time for B
Using equation of motion
Put the value in the equation
We need to calculate the time for longest nap
Using formula for difference of time
Hence, B can take 0.64 sec for the longest nap .
I think you can just sub the values in? unless the qn is asking for smth else?
