ANSWER: NATURE
EXPLAINTION:
To that multiply 1.9 by 5 to get 9.5. The zebra has gone 9.5 m.
B.
We know that the definition of acceleration is the rate of change of velocity. Moreover, velocity is a vector quantity, so it has both magnitude and direction. While moving in a circle, the direction of the car's velocity is constantly changing. This change means that the velocity of the car is changing. Because the velocity is changing, the car is accelerating, despite the magnitude of the velocity remaining the same.
OK. So you're pushing on the small box, and on the other side of it, the small
box is pushing on the big box. So you're actually pushing both of them.
-- The total mass that you're pushing is (5.2 + 7.4) = 12.6 kg.
-- You're pushing it with 5.0N of force.
-- Acceleration of the whole thing = (force)/(mass) = 5/12.6 = <em>0.397 m/s²</em> (rounded)
-- Both boxes accelerate at the same rate. So the box farther away from you ...
the big one, with 7.4 kg of mass, accelerates at the same rate.
The force on it to make it accelerate is (mass) x (acceleration) =
(7.4 kg) x (5/12.6 m/s²) = <em>2.936 N.</em>
The only force on the big box comes from the small box, pushing it from behind.
So that same <em>2.936N</em> must be the contact force between the boxes.