A device made from a coil of wire that carries a current and produces a magnetic field is called a <span>solenoid. </span><span>✅
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Answer: Letter B
Hope that helps. -UF aka Nadia</span>
Answer: Taking into account sound is a wave, we can use the information of the displacement (generally given as a graph) to find the wavelength and frequency, then we can calculate the speed with the formula of the speed of a wave.
Explanation:
If we have the displacement graph of the sound wave, we can find its amplitude, its wavelength and period (which is the inverse of frequency).
Now, if we additionally have the frequency as data, we can use the equation of the speed of a wave:

Where:
is the speed of the sound wave
is the wavelength
is the frequency
Answer:
The pressure on the floor is 12 Pascal(Pa).
Explanation:
Given,
Force (F) = 240N
Area (A) = 20 cm^2
Pressure (P) = ?
we know that,
P = F/A
= 240/ 20
= 12 Pa
Answer:

Explanation:
= Permittivity of free space = 
= Surface charge density = 
= 0.57-0.26
q = Charge = 
m = Mass of object = 
Electric field due to a sheet is given by

Electric field is given by

Voltage is given by

Kinetic energy is given by


The initial speed of the object is 
Answer:
C) 4.0 m/s²
Explanation:
Given data
- Applied force (F): 120 Newton
- Mass of the object (m): 30 kilograms
- Acceleration of the object (a): to be determined
We can find the acceleration of the object using Newton's second law of motion.
F = m . a
a = F / m = 120 N / 30 kg = 4.0 m/s²
The acceleration of the object is 4.0 m/s².