Answer is B. According to the equation of motion s = vt + 1/2 at2 Where s is distance covered, v is velocity, a is acceleration and t is time taken. So, by putting all the values, we get s = (20)(5) + 1/2 (3)(5)2 s = 100 + 1/2 (3)(25) s = 100 + 1/2 75 s = 100 + 37.5 s = 137.5 meters
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
Answer:
The unit of power is pascal.
Answer:
Explanation:
a Downward acceleration of car A along the slope
= g sinθ - μ g cosθ
= g ( sinθ - μ cosθ)
= 9.8 ( sin 12 - .6 x cos 12 )
= 9.8 x ( .2079 - .5869 )
= - 3.714 m / s²
So there will be deceleration
v² = u² - 2 a s
= 18² - 2 x 3.714 x 24
= 324 - 178
= 146
v = 12 .08 m /s
b )
In the second case , kinetic friction changes
downward acceleration
= g ( sinθ - μ cosθ)
= 9.8 ( sin12 - .1 x cos 12 )
9.8 ( .2079 - .0978 )
= 1.079 m /s
there will be reduced acceleration
v² = u² - 2 a s
= 18² +2 x1.079 x 24
= 324 + 52
= 376
v = 19.4 m /s