Answer:

Explanation:
q = Charge
r = Distance




The electric field is given by

The electric field at the aircraft is 
Answer:
The net change in the internal energy of the gas in the piston is -343J
Explanation:
Because heat and workdone are the only means of energy transfer between the system and the surrounding, change in internal energy is given by;
∆E = q + w
q = heat transfer
w = workdone
Because heat is lost by the system, the heat transfer is negative
q = -413J
Because work is done on the system, workdone is positive
w = +70J
∆E = -413J + 70J
∆E = -343J
Answer:
C?
Explanation:
My best guess would be C as it's the only answer that gives a reason behind the statement.
Answer:
The minimum frequency required to ionize the photon is 111.31 ×
Hertz
Given:
Energy = 378 
To find:
Minimum frequency of light required to ionize magnesium = ?
Formula used:
The energy of photon of light is given by,
E = h v
Where E = Energy of magnesium
h = planks constant
v = minimum frequency of photon
Solution:
The energy of photon of light is given by,
E = h v
Where E = Energy of magnesium
h = planks constant
v = minimum frequency of photon
738 ×
= 6.63 ×
× v
v = 111.31 ×
Hertz
The minimum frequency required to ionize the photon is 111.31 ×
Hertz
Answer: Contact force
a. Applying break in a vehicle.
d. The speed of ball rolling on ground is reduced
Non contact force
b. A coconut falling from a coconut tree.
c. The planets revolving around the sun.
Explanation:
The contact force is the force which exerts when one object or entity comes in contact with other object or entity. For example, on application of break the vehicle stops, the force is applied on the breaks to stop the vehicle. The ball rolling on the ground the speed reduces so the application of force on the ground also reduces.
The non contact force is the force one object exerts on the other without coming in direct contact with the other object. The force exerted by one object on other due to gravity is a non contact force. The coconut falling on the ground and planets revolving around the sun are examples of non contact force due to gravity.