Answer:
129 J/Kg°C
Explanation:
Given :
Mass of gold, m = 1.2kg
Quantity of heat applied, Q = 3096 J
Temperature, t2 = 40°C
Temperature, t1 = 20°C
Change in temperature, dt = (40-20)°C = 20°C
Using the relation :
Q = mcdt
Where, C = specific heat capacity of gold
3096 = 1.2kg * C * 20°C
3096 J = 24kg°C * C
C = 3096 J / 24 kg°C
C = 129 J/Kg°C
Answer:
C) Contact
Explanation:
The magnet requires almost direct <u>contact</u> with the fridge to start its magnetic properties.
A) 
The total energy of the system is equal to the maximum elastic potential energy, that is achieved when the displacement is equal to the amplitude (x=A):
(1)
where k is the spring constant.
The total energy, which is conserved, at any other point of the motion is the sum of elastic potential energy and kinetic energy:
(2)
where x is the displacement, m the mass, and v the speed.
We want to know the displacement x at which the elastic potential energy is 1/3 of the kinetic energy:

Using (2) we can rewrite this as

And using (1), we find

Substituting
into the last equation, we find the value of x:

B) 
In this case, the kinetic energy is 1/10 of the total energy:

Since we have

we can write

And so we find:

Answer:
T is less than or equal to 19 N
Explanation: