The field around a solenoid is:
a) similar to a bar magnet
b) unipolar
c) nonsymmetrical

A) similar to a bar magnet

Explanation:

As we know that solenoid is similar to a bar magnet and the magnetic field is similar to the bar magnet

So here magnetic field due to a bar magnet is given by

so here one of its end behaves like north pole while other end behaves like a south pole

Here magnetic field is of maximum field strength at the ends of the poles and it is decreasing in similar way as that of bar magnet

So here we can say that correct answer will be

A) similar to a bar magnet

what was the acceleration of the 2 kg cart?

⇒ 16.0 cm/s2

what was the acceleration of the 4 kg cart?

⇒ 8.1 cm/s2

what was the acceleration of the 6 kg cart?

⇒ 5.3 cm/s2

nah.   i'm just sleepy.