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
Answer:
A) B = 5.4 10⁻⁵ T, B) the positive side of the bar is to the West
Explanation:
A) For this exercise we must use the expression of Faraday's law for a moving body
fem = 
fem =
- d (B l y) / dt = - B lv
B = 
we calculate
B = - 7.9 10⁻⁴ /(0.73 20)
B = 5.4 10⁻⁵ T
B) to determine which side of the bar is positive, we must use the right hand rule
the thumb points in the direction of the rod movement to the south, the magnetic field points in the horizontal direction and the rod is in the east-west direction.
Therefore the force points in the direction perpendicular to the velocity and the magnetic field is in the east direction; therefore the positive side of the bar is to the West
Answer:
1
The mass of the Potassium-40 is 
2
The Dose per year in Sieverts is 
Explanation:
From the question we are told that
The isotopes of potassium in the body are Potassium-39, Potassium-40, and Potassium-
41
Their abundance is 93.26%, 0.012% and 6.728%
The mass of potassium contained in human body is
per kg of the body
The mass of the first body is 
Now the mass of potassium in this body is mathematically evaluated as

substituting value


The amount of Potassium-40 present is mathematically evaluated as
0.012% * 0.024


The dose of energy absorbed per year is mathematically represented as

Where E is the energy absorbed which is given as 
Substituting value


The Dose in Sieverts is evaluated as



Answer with Explanation:
We are given that mass of block=0.0600 kg
Initial speed of block=0.63 m/s
Distance of block from the hole when the block is revolved=0.47 m
Final speed=3.29 m/s
Distance of block from the hole when the block is revolved=
a.We have to find the tension in the cord in the original situation when the block has speed =

Because tension is equal to centripetal force
Substitute the values

b.

c.Work don=Final K.E-Initial K.E



As you go from Radio waves across to Gamma eats : Wavelength decreases and frequency and energy increase.