Answer: 20.4m
Explanation:
Mass = 0.145kg
Initial velocity, Vi =20m/s
Initial kinetic energy K =1/2mv^2
Initial potential energy Ui = mgx = 0joules
: From conservation of energy,
Uf + Kf = Ui + Ki ( where f represent (final) )
Thus
mgXf + 0 = 0+1/2 mv^2
Xf = Vi^2/ 2g
= (20m/s) ^2/ 2(9.81m/s)^2
=20.4m
Mechanical Wave cannot travel in space vaccumes, which would be considered "Empty Space" in your situation.
1000000
Explanation
No equation for the following question was given
Kinematic question!
Start with your knowns!

we want to find x!
the only kineamtic that works with this info is the third!

so we plug in our values and get

this'll equal out to -159.2 meters.
our units equal out, so we know our answer is correct!
Answer:
Electromagnets are very widely used in electric and electromechanical devices, including:
Motors and generators.
Transformers.
Relays.
Electric bells and buzzers.
Loudspeakers and headphones.
Actuators such as valves.
Magnetic recording and data storage equipment: tape recorders, VCRs, hard disks.