Answer:
a. keeps its speed for a short while, then slows and stops. slows steadily until it stops.
Explanation:
Since the tension in the rope, t is greater than the kinetic friction fk, the box is moving forward because there is a net force on it. That is, t - fk = f = ma.
Since there is a net force, there is an acceleration and thus an increasing velocity.
When the rope breaks, the tension, t = 0. So, t - fk = 0 - fk = -fk = ma'.
Now, the net force acting on the box is friction in the opposite direction. This force tends to slow the box down from its initial velocity at acceleration, 'a' until its velocity is zero, where it stops. Since the frictional force is constant, the acceleration, a' on the box is thus constant and the box undergoes uniform deceleration until its velocity is zero.
<u>So, the box keeps its speed for a short while, then slows and stops. slows steadily until it stops.</u>
So, the answer is a.
Answer: 2.83 minutes
Explanation:
It is understood that trains are approaching. That is, they have speeds of equal magnitude but opposite. When train A travels x meters northbound, then train B travels the same distance southbound.
Therefore trains approach at a speed of:

Then:

Where x is the distance between the trains

So the time in which both trains meet is:

This is:

<em />
<em>How long will it be before they reach one another ?</em>
<h3>2.83 minutes</h3>
Answer:
A negative potential energy becomes more negative
Explanation:
Let the charges be - Q₁ and Q₂ . Let the distance between them be d .
Potential energy = k -Q₁x Q₂ / R
= - KQ₁ Q₂ / R
Now if the magnitude of R decreases , the magnitude of potential energy increases . So we see that the negative potential energy becomes more negative .
Answer:

Explanation:
From the question we are told that
Distance 
Time
Time
Generally the the equation for the distance traveled is mathematically given as



Generally equation for speed of side walk is mathematically given as




Answer:
The Gravity gets stronger
Explanation:
Newtons laws of motion.