Answer:
3120J
Explanation:
Given parameters:
C = Specific heat capacity = 0.8J/g°C
Initial temperature = 20°C
Mass given = 5g
Final temperature = 800°C
Unknown:
Energy given to the mass = ?
Solution:
To find the energy given to the mass, let us simply use the expression below:
H = m c ΔT
H is the unknown, the energy supplied
m is the mass of the substance
c is the specific heat capacity
ΔT is the change in temperature
Input the variables;
H = 5 x 0.8 x (800 - 20) = 3120J
Answer:
Explanation:
Given
Initial Intensity of light is S
when an un-polarized light is Passed through a Polarizer then its intensity reduced to half.
When it is passed through a second Polarizer with its transmission axis 

here 


When it is passed through third Polarizer with its axis
to first but
to second thus 



When middle sheet is absent then Final Intensity will be zero
Answer:
Tension, T = 87.63 N
Explanation:
Given that,
Mass of the object, m = 6.9 kg
The string is acting in the upward direction, a = 2.9 m/s²
Acceleration due to gravity, g = 9.8 m/s²
As the lift is accelerating upwards, it means the net force acting on it is given by :
T = m(a+g)
= 6.9 (2.9+9.8)
= 6.9(2.7)
= 87.63 N
So, the tension in the string is 87.63 N.