-- With two resistors in parallel, the total effective resistance is
the reciprocal of (1/R₁ + 1/R₂).
1/R₁ + 1/R₂ = 1/15 + 1/40
= 8/120 + 3/120
= 11/120
So the total effective resistance is 120/11 = 10.9 ohms .
Current = (voltage) / (resistance)
= 12 / (120/11)
= (12 · 11) / 120
= 132/120 = 1.1 Amperes
Answer:
they meet from point o at distance 50.46 m and time taken is 11.6 seconds
Explanation:
given data
acceleration = 0.75 m/s²
speed B = 6 m/s
time B = 20 s
to find out
when and where the vehicles passed each other
solution
we consider here distance = x , when they meet after o point
and time = t for meet point z
we find first Bus B distance for 20 s ec
distance B = velocity × time
distance B = 6 × 20
distance B = 120 m
so
B take time to meet is calculate by distance formula
distance = velocity × time
120 - x = 6 × t
x = 120 - 6t .................1
and
distance of A when they meet by distance formula
distance = ut + 1/2 × at²
here u is initial speed = 0 and t is time
x = 0 + 1/2 × 0.75 × t²
x = 0.375 × t² .............2
so from equation 1 and 2
0.375 × t² = 120 - 6t
t = 11.6
so time is 11.6 second
and
distance from point o from equation 2
x = 0.375 (11.6)²
x = 50.46
so distance from point o is 50.46 m
Option (a) is correct.
Change in volume during the band concert might have been caused by the constructive and destructive interference of sound waves.
Interference is the process of redistribution of energy when two or more waves superimpose on each other.When two sound waves which are in phase superimpose on each other, constructive interference takes place. During constructive interference , the amplitude of resulting waves increases.Thus the loudness of sound increases.
When two sound waves which are out of phase superimpose on each other, destructive interference takes place. During destructive interference , the amplitude of resulting waves decreases.Thus the loudness of sound decreases.
Answer:
-78.96 J
Explanation:
The workdone by the torque in stopping the wheel = rotational kinetic energy change of wheel.
So W = 1/2I(ω₁² - ω₀²) where I = rotational inertia of wheel = 0.04 kgm², r = radius of wheel = 0.02 m, ω₀ = initial rotational speed = 10 rev/s × 2π = 62.83 rad/s, ω₁ = final rotational speed = 0 rad/s (since the wheel stops)
W = 1/2I(ω₁² - ω₀²) = 1/2 0.04 kgm² (0² - (62.83 rad/s)²) = -78.96 J
Answer:
Option d)
Solution:
As per the question:
Work done by farm hand, 
Force exerted, F' = 310 N
Angle, 
Now,
The component of force acting horizontally is F'cos
Also, we know that the work done is the dot or scalar product of force and the displacement in the direction of the force acting on an object.
Thus
d = 3.406 m = 3.4 m
