A 2.80 kg mass is dropped from a height of 4.50 m. Find its kinetic
energy (KE) when it is 3.00 m
above the ground. PLEASE HELP!!!

82.32 J

Explanation:

Given:

Mass,  

Initial height,  

Final height,  

As the mass is dropped, its initial velocity is 0 m/s.

So, initial kinetic energy is also 0 J.

Now, according to conservation of energy,

Increase in Kinetic energy is equal to the decrease in potential energy.

Here, Decrease in potential energy is given as,

Δ

Now, increase in kinetic energy is equal to the kinetic energy at height  as the initial kinetic is 0.

∴ Kinetic energy at height 1.50 m above ground is given as the decrease in potential energy.

So, Kinetic energy = Decrease in potential energy =  

Kinetic energy at height 1.50 m above ground is .

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation:

answer: electrons