Ahockey pack is set in motion across a frozen pond. if the ice friction and air resistance are neglected, the force required to keep the pack sliding at constant velocity is a) zero newtons. b) equal to the weight of the pack. c) the weight of the pack divided by the mass of the pack. d) the mass of the pack multiplied by 9.8 meters per second per second. e) none of these.

A) Zero newtos

Explanation:

To solve this exercise, let's use Newton's first and second law, in the first law it is established that every body is at rest or moving with constant speed if the external forces are zero. In the second law it is determined that the sum of the force is proportional to the acceleration of the body.

Let us apply our case, the body is at constant speed which implies that the sum of all external forces is zero. In addition, there is no friction, so we do not need a force that counteracts them.

Consequently, the force applied must be zero.  

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