Hello there..
<span>Which of the following statements is TRUE?
</span>D. Light waves are electromagnetic waves and sound waves are mechanical waves.
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
The initial speed of the shot is 15.02 m/s.
The Shot put is released at a height y<em> </em>from the ground with a speed u. It is released at an angle θ to the horizontal. In a time t, the shot put travels a distance <em>R</em> horizontally.
Pl refer to the attached diagram.
Resolve the velocity u into horizontal and vertical components, u ₓ=ucosθ and uy=u sinθ. The horizontal component remains constant in the absence of air resistance, while the vertical component varies due to the action of the gravitational force.
Write an expression for R.
Therefore,
In the time t, the net displacement of the shotput is y in the downward direction.
Use the equation of motion,
Substitute the value of t from equation (1).
Substitute -2.10 m for y, 24.77 m for R and 38.0° for θ and solve for u.
The shot put was thrown with a speed 15.02 m/s.
Answer: A physical change can be a change in size, shape, or color.
Explanation:
One type of physical change is a phase change. Consider water for example, if liquid water evaporated into a vapor, a phase change occurred. A phase change is a type of physical change. The difference between a physical change and chemical change is that a physical change doesn't change the substance identity. A chemical change can however change the identity of the substance.
