Hi there!
Assuming the track is frictionless:

Cancel out the masses and rearrange to solve for velocity:

Plug in the given height and let g = 9.8 m/s²:

Answer:
1.53seconds
Explanation:
Using first equation of motion :
V=U + at
Where final velocity (V) =+8.3m/s
Initial velocity (U) =+4.4m/s
Acceleration (a) = 0.65m/s^2
time(s)=?
V=U + at
+8.3^2 = +4.4 + 0.65 * t
Making t the subject of the formula :
Therefore, t= ( +8.3 - 4.4)/0.65 = 1.53seconds
Answer:
hmm
Explanation:
By increasing the number of turns in the coil, strength of magnetic field, speed of rotation of the coil in the magnetic field and by decreasing the distance between the coil and the magnet the magnitude of the induced e.m.f. can be increased in generator/dynamo.
Newtons first law of motion is also known as the law of inertia
F=ma therefore 25kg*1.0m/s^2=25N force on the mass