Answer:

Explanation:
First we need to state our assumptions:
Thermal properties of ice and water are constant, heat transfer to the glass is negligible, Heat of ice 
Mass of water,
.
Energy balance for the ice-water system is defined as

a.The mass of ice at
is defined as:
![[mc(0-T_1)+mh_i_f+mc(T_2-0)]_i_c_e+[mc(T_2-T_1)]_w=0\\\\m_i_c_e[0+333.7+418\times(5-0)]+0.3\times4.18\times(5-20)=0\\m_i_c_e=0.0546Kg=54.6g](https://tex.z-dn.net/?f=%5Bmc%280-T_1%29%2Bmh_i_f%2Bmc%28T_2-0%29%5D_i_c_e%2B%5Bmc%28T_2-T_1%29%5D_w%3D0%5C%5C%5C%5Cm_i_c_e%5B0%2B333.7%2B418%5Ctimes%285-0%29%5D%2B0.3%5Ctimes4.18%5Ctimes%285-20%29%3D0%5C%5Cm_i_c_e%3D0.0546Kg%3D54.6g)
b.Mass of ice at
is defined as:
![[mc(0-T_1)+mh_i_f+mc(T_2-0)]_i_c_e+[mc(T_2-T_1)]_w=0\\\\m_i_c_e[2.11\times(0-(20))+333.7+4.18\times(5-0)]+0.3\times4.18\times(5-20)=0\\\\m_i_c_e=0.0487Kg=48.7g](https://tex.z-dn.net/?f=%5Bmc%280-T_1%29%2Bmh_i_f%2Bmc%28T_2-0%29%5D_i_c_e%2B%5Bmc%28T_2-T_1%29%5D_w%3D0%5C%5C%5C%5Cm_i_c_e%5B2.11%5Ctimes%280-%2820%29%29%2B333.7%2B4.18%5Ctimes%285-0%29%5D%2B0.3%5Ctimes4.18%5Ctimes%285-20%29%3D0%5C%5C%5C%5Cm_i_c_e%3D0.0487Kg%3D48.7g)
c.Mass of cooled water at 

![[mc(T_2-T_1)]_c_w+[mc(T_2-T_1)]_w=0\\m_c_w\times4.18\times(5-0)+0.3\times4.18\times(5-20)\\m_c_w=0.9kg=900g](https://tex.z-dn.net/?f=%5Bmc%28T_2-T_1%29%5D_c_w%2B%5Bmc%28T_2-T_1%29%5D_w%3D0%5C%5Cm_c_w%5Ctimes4.18%5Ctimes%285-0%29%2B0.3%5Ctimes4.18%5Ctimes%285-20%29%5C%5Cm_c_w%3D0.9kg%3D900g)
Answer:

Explanation:
= Rate at which the distance between A and starting point of B is changing = -20 km/h
= Rate at which the distance of B is changing = 15 km/h
= Rate at which the distance between A and B is changing
Time after which the rate at which the distance between A and B is changing is 4 hours
Distance covered by A in 4 hours = 
a = Distance remaining to the start point of B = 
b = Distance covered by B in 4 hours = 
Distance between A and B after 4 hours


Differentiating with respect to time we get

The rate at which the distance between the ships is changing at 4 PM is
.
Answer:
0.03605 V/m is the electric field in the gold wire.
Explanation:
Resistivity of the gold = 
Length of the gold wire = L = 14 cm = 0.14 m ( 1 cm = 0.01 m)
Diameter of the wire = d = 0.9 mm
Radius of the wire = r = 0.5 d = 0.5 × 0.9 mm = 0.45 mm = 
( 1mm = 0.001 m)
Area of the cross-section = 
Resistance of the wire = R
Current in the gold wire = 940 mA = 0.940 A ( 1 mA = 0.001 A)

( Ohm's law)

We know, Electric field is given by :




0.03605 V/m is the electric field in the gold wire.
Answer:
See below
Explanation:
Vertical position = 45 + 20 sin (30) t - 4.9 t^2
when it hits ground this = 0
0 = -4.9t^2 + 20 sin (30 ) t + 45
0 = -4.9t^2 + 10 t +45 = 0 solve for t =4.22 sec
max height is at t= - b/2a = 10/9.8 =1.02
use this value of 't' in the equation to calculate max height = 50.1 m
it has 4.22 - 1.02 to free fall = 3.2 seconds free fall
v = at = 9.81 * 3.2 = 31.39 m/s VERTICAL
it will <u>also</u> still have horizontal velocity = 20 cos 30 = 17.32 m/s
total velocity will be sqrt ( 31.39^2 + 17.32^2) = 35.85 m/s
Horizontal range = 20 cos 30 * t = 20 * cos 30 * 4.22 = 73.1 m
Answer:
False
Explanation:
From the fact that light is emitted in portion, it does not follow that light ray is discrete in structure.
The way Einstein put it was that if a beer is always sold in pint bottles, that does not mean that beer contain of indivisible pint bottles. Yet experiments in which light knocked electrons out of materials insistently made the point that light is absorbed only in the form of discrete portions. An emitted portion or quantum of light energy retains it's individuality in subsequent events as well.
This concept was first stated by Einstein in 1905. From the heuristic point of view that he developed light is always made up of discrete portions possessing energy and momentum.