Answer:
v= 300 m/s
Explanation:
Given that
altitude ,h= 4500 m
The mass ,m = 3 kg
Lets take acceleration due to gravity , g= 10 m/s²
The speed before impact at sea level = v
Initial speed ,u = 0 m/s
We know that
v²=u²+2 g h
v=final speed
u=initial speed
h=height
Now by putting the values in the above equation
v² = 0²+ 2 x 10 x 4500
v²=90000
v= 300 m/s
Therefore the speed at sea level will be 300 m/s.
Answer:
E = h f and since f = c / λ we have E = h c / λ
Thus λ = h c / E
Also, 1 ev = 1.6E-19 C
λ = 6.63E-34 * 3.0E8 / (1.6 * 1.6E-19)
λ = 6.63 * 3.0 / (1.6 * 1.6) * E-7
λ = 7.77E-7 = 777 nanometers
(B) is correct
Answer:
it increases by a factor 1.07
Explanation:
The peak wavelength of an object is given by Wien's displacement law:
(1)
where
b is the Wien's displacement constant
T is the temperature (in Kelvins) of the object
given the relationship between frequency and wavelength of an electromagnetic wave:
where c is the speed of light, we can rewrite (1) as
So the peak frequency is directly proportional to the temperature in Kelvin.
In this problem, the temperature of the object changes from
to
so the peak frequency changes by a factor
Answer:
in the acceleration process the quantity α and w must increase
the deceleration process the alpha quantity must constant a direction opposite to the angular velocity
Explanation:
Acceleration and angular velocity are related to linear
v = w xr
a = αx r
The bold letters indicate vectors and the cross is a vector product, therefore if
we can see that the relationship between linear and angular variables is direct
therefore in the acceleration process the quantity α and w must increase as well as their linear counterparts
in the deceleration process the alpha quantity must constant as the linear acceleration and must have a direction opposite to the angular velocity
A flow of electric charge from one place to another is electric 'current'.
Also:
When you post a multiple-choice question,
please post the choices along with it.
Thank you.
