Answer:
Incomplete questions
Let assume we are asked to find
Calculate the induced emf in the coil at any time, let say t=2
And induced current
Explanation:
Flux is given as
Φ=NAB
Where
N is number of turn, N=1
A=area=πr²
Since r=2cm=0.02
A=π(0.02)²=0.001257m²
B=magnetic field
B(t)=Bo•e−t/τ,
Where Bo=3T
τ=0.5s
B(t)=3e(−t/0.5)
B(t)=3exp(-2t)
Therefore
Φ=NAB
Φ=0.001257×3•exp(-2t)
Φ=0.00377exp(-2t)
Now,
Induce emf is given as
E= - dΦ/dt
E= - 0.00377×-2 exp(-2t)
E=0.00754exp(-2t)
At t=2
E=0.00754exp(-4)
E=0.000138V
E=0.138mV
b. Induce current
From ohms laws
V=iR
Given that R=0.6Ω
i=V/R
i=0.000138/0.6
i=0.00023A
i=0.23mA
Here, we know, according to 3rd Equation of Kinematics,
v² - u² = 2as
Here, u = 0 [ Free fall ]
a = 9.8 m/s² [ constant value for the Earth system ]
s = 15 m
Substitute their values,
v² - 0² = 2 * 9.8 * 15
v² = 294
v = √294
v = 17.15 m/s
In short, Your Answer would be Option D
Hope this helps!
Answer:

Explanation:
Speed = Distance / Time
So, to find distance, we actually divide distance by rime.
Answer:
The moment of inertia of the wood sphere is greater than that of
the one made of lead.
Explanation: