Answer:
a) E = 0.0048 Volts
b) dA/dt = - 0.002285 m²/s
Explanation:
Given:
Area, A = 0.020 m²
Rate of change of magnetic field, dB/dt = 0.24 T/s
a) The magnitude of the emf induced (E) is given as:
E= A × (dB/dt)
on substituting the values in the above equation, we get
E = (0.020 m²) × (0.24 T/s)
or
E = 0.0048 Volts
b) Now, The induced emf when both the area and the magnetic field is varying
we have
E = B(dA/dt) + A(dB/dt)
Now, for the given case induced emf is zero i.e E = 0 and magnetic field B = 2.1 T
thus,
0 = (2.1 T)(dA/dt) + (0.020 m2)(0.24 T/s)
dA/dt = - 0.002285 m²/s
Hence, the area should be decreased at the rate of 0.002285 m²/s
An effect whereby a mass moving in a rotating system experiences a force (the Coriolis force ) acting perpendicular to the direction of motion and to the axis of rotation. On the earth, the effect tends to deflect moving objects to the right in the northern hemisphere and to the left in the southern and is important in the formation of cyclonic weather systems.
Solution :
Given weight of Kathy = 82 kg
Her speed before striking the water,
= 5.50 m/s
Her speed after entering the water,
= 1.1 m/s
Time = 1.65 s
Using equation of impulse,

Here, F = the force ,
dT = time interval over which the force is applied for
= 1.65 s
dP = change in momentum
dP = m x dV
![$= m \times [V_f - V_o] $](https://tex.z-dn.net/?f=%24%3D%20m%20%5Ctimes%20%5BV_f%20-%20V_o%5D%20%24)
= 82 x (1.1 - 5.5)
= -360 kg
∴ the net force acting will be


= 218 N
Answer:
The specific gravity of the unkown liquid is 15.
Explanation:
Gauge pressure, at the bottom of the tank in this case, can be calculated from

where
and
are the height of the column of oil and the unkown liquid, respectively. Writing for
, we have

Relative to water, the unknow liquid specific weight is 15 times bigger, therefore this is its specific gravity as well.
Answer:
Too much screen time can be a bad thing: Children who consistently spend more than 4 hours per day watching TV are more likely to be overweight. Kids who view violent acts on TV are more likely to show aggressive behavior, and to fear that the world is scary and that something bad will happen to them. When we considered the whole television chain of production, distribution and consumption, we found that the largest environmental impact associated with a television programme was not the energy consumed in making it, but the energy used by the millions of televisions, set-top boxes and other consumer devices involved
Explanation: