Answer:
<em>262.4 m/s</em>
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Explanation:
The complete question is 
If we ignore air resistance, a falling body will fall 16t^2 feet in t seconds. What is the average velocity between t=8 and t=8.4? Round your answer to two decimal places if necessary.
The distance fallen s = 16t^2
The velocity v =  = 32t
 = 32t
If we substitute the values of t into the velocity v, we'll have
at t = 8 s,     V1 = 32 x 8 = 256 m/s
at t = 8.4 s,  V2 = 32 x 8.4 = 268.8 m/s
Average velocity = (V2 - V1)/2 = (268.8 + 256)/2 = <em>262.4 m/s</em>
 
        
             
        
        
        
Answer:
86 turns
Explanation:
Parameters given:
Magnetic torque, τ = 1.7 * 10^(-2) Nm
Area of coil, A = 9 * 10^(-4) m²
Current in coil, I = 1.1 A
Magnetic field, B = 0.2 T
The magnetic toque is given mathematically as:
τ = N * I * A * B
Where N = number of turns
To find the number of turns, we make N subject of formula:
N = τ/(I * A * B)
Therefore:
N = (1.7 * 10^(-2)) / (1.1 * 9 * 10^(-4) * 0.2)
N = 85.85 = 86 turns (whole number)
The number of turns must be 86.
 
        
             
        
        
        
Explanation:
Below is an attachment containing the solution 
 
        
             
        
        
        
Answer:
the object has least potential energy at mean position of the SHM
Explanation:
If a block is connected with a spring and there is no resistive force on the system 
In this case the total energy of the system is always conserved and it will change from one form to another form
So here we will say that
Kinetic energy + Potential energy = Total Mechanical energy
As we can say that total energy is conserved so here we have least potential energy when the system has maximum kinetic energy
So here we also know that at mean position of the SHM the system has maximum speed and hence maximum kinetic energy.
So the object has least potential energy at mean position of the SHM