Answer:
The mass of the aluminum chunk is 258 g
Explanation:
Given;
mass of steel container = 120-g
mass of water = 150 g
initial temperature of water, = 25°C
mass of copper cube, 
= 200 g
initial temperature of the copper cube, 
= 85°C
initial temperature of the aluminum chunk 
= 5.0°C
Neglecting heat loss, heat exchanged by the two metallic objects is the same since initial temperature is equal to final temperature of water.
where;
is specific heat capacity of aluminum
is change in temperature of aluminum
is the specific heat capacity of copper
is the change in temperature of copper
Therefore, the mass of the aluminum chunk is 258 g
Answer:
answer is friction. MCQ A is answer
Answer:
Explanation:
Given that,
Assume number of turn is
N= 1
Radius of coil is.
r = 5cm = 0.05m
Then, Area of the surface is given as
A = πr² = π × 0.05²
A = 7.85 × 10^-3 m²
Resistance of
R = 0.20 Ω
The magnetic field is a function of time
B = 0.50exp(-20t) T
Magnitude of induce current at
t = 2s
We need to find the induced emf
This induced voltage, ε can be quantified by:
ε = −NdΦ/dt
Φ = BAcosθ, but θ = 90°, they are perpendicular
So, Φ = BA
ε = −NdΦ/dt = −N d(BA) / dt
A is a constant
ε = −NA dB/dt
Then, B = 0.50exp(-20t)
So, dB/dt = 0.5 × -20 exp(-20t)
dB/dt = -10exp(-20t)
So,
ε = −NA dB/dt
ε = −NA × -10exp(-20t)
ε = 10 × NA exp(-20t)
Now from ohms law, ε = iR
So, I = ε / R
I = 10 × NA exp(-20t) / R
Substituting the values given
I = 10×1× 7.85 ×10^-3×exp(-20×2)/0.2
I = 1.67 × 10^-18 A
Answer:
I think it's 2 the photo is hard to tell what they are exactly talking about.
