Answer:
8.51 m/s
Explanation:
Velocity = Displacement/Time
Velocity = 400 m ÷ 47 s
<u>Velocity</u><u> </u><u>=</u><u> </u><u>8</u><u>.</u><u>5</u><u>1</u><u> </u><u>m</u><u>/</u><u>s</u>
Answer:
a) -3.267 m/s
b) 2.227 m/s
Explanation:
As per the conservation of momentum
m1v1 + m2v2=0
m1= mass of log
m2 = mass of lumber jack
v1 = velocity of log
v2 = velocity of lumber jack
a) Velocity of first log
m/s
b) m1v1 + m2v2 = m3v3
Velocity of log
= 
Answer:
a) 298.5 nm
, 522.4 nm and b) radiation frequency does not change
Explanation:
When electromagnetic radiation reaches a medium with a different index of refraction, the medium vibrates the molecules, as if it were a resonance process, whereby the medium vibrates at the same frequency as the incident light.
On the other hand, when the light reaches another medium its average speed within the medium changes, it is now less than the speed of light in a vacuum (c) for this to happen as we saw that the frequency is constant there must be a change in the wavelength of the radiation that is characterized by the ratio
λₙ = λ₀ / n
λₙ = 400 nm in the void
λₙ = 400 / 1.34
λₙ= 298.5 nm
λ₀ = 700 nm
λₙ = 700 / 1.34
λₙ = 522.4 nm
The radiation frequency does not change
Answer:
31.75 m/s
Explanation:
h = 41.7 m
Let the initial velocity of the second stone is u
Let the time taken to reach to the bottom by the first stone is t then the time taken by the second stone to reach the ground is t - 1.8.
For first stone:
Use second equation of motion

Here, u = 0, g = 9.8 m/s^2 and t be the time and h = 41.7
So, 41.7= 0 + 0.5 x 9.8 x t^2
41.7 = 4.9 t^2
t = 2.92 s ..... (1)
For second stone:
Use second equation of motion

Here, g = 9.8 m/s^2 and time taken is t - 1.8 = 2.92 - 1.8 = 1.12 s, h = 41.7 m and u be the initial velocity
.... (2)
By equation the equation (1) and (2), we get

u = 31.75 m/s
<h2>The man have to apply force of 160 N</h2>
Explanation:
The work done to lift the bag of weight mg through height 2.5 m is 400 J
The work done can be found by relation W = mg x h
Thus mg =
=
= 160 N
Therefore the man have to apply the force of 160 N