Name: Lead
Symbol: Pb
Atomic Number: 82
Atomic Mass: 207.2 amu
Melting Point: 327.5 °C (600.65 K, 621.5 °F)
Boiling Point: 1740.0 °C (2013.15 K, 3164.0 °F)
Number of Protons/Electrons: 82
Number of Neutrons: 125
Classification: Other Metals
Crystal Structure: Cubic
Density @ 293 K: 11.34 g/cm3
Color: bluish
1) 29.5 N/m
2) 0.100 m
Explanation:
1)
The force constant of the spring can be found by using the fact that the force on the spring is proportional to the extension of the spring (Hooke's Law). Therefore, we can write:

where
is the change in the force on the spring, where
is the force applied when the hanging mass is

is the force applied when the hanging mass is

is the change in extension of the spring, where
is the extension of the spring when the hanging mass is 0.300 kg
is the extension of the spring when the hanging mass is 1.95 kg
Solving for k,

2)
When the first mass is hanging on the spring, we have

where:
is the force applied on the spring (the weight of the hanging mass)
k is the spring constant
is the extension of the spring wrt its natural length
is the natural length of the spring (the unloaded length)
Here we have

k = 29.5 N/m

Solving for
, we find:

Answer:
(a) Relative speed of Sam = -7 mph
(b) Relative speed of George = 7 mph
Explanation:
We have given speed of Sam 65 mph in north direction.
And speed of George is 72 mph also in north direction
We have find the relative velocity of both Sam and George
(a) Speed of Sam relative to George = speed of Sam - speed of George = 65 -72 = -7 mph
(b) Speed of George with respect to Sam = speed of George - speed of Sam = 72-65 = 7 mph
Answer:
λ = 470.66 nm
Explanation:
for bright fringe
D= distance between slit and screen
d= distance between the slits
for first order bright fringe m = 1,


for dark fringe,we have
Now to get the dark fringes at the same location we should have;
(706)D/d = (m + 1/2)λD/d
put m = 1
(1 + 1/2)λ = (706)
λ = 470.66 nm