Question

A 30.0 kg box hangs from a rope. What is the tension (in N) in the rope if the box has an initial velocity of 2.0 m/s and is slowing down at 2.0 m/s2?

Answer 1

360 N

Step-by-step explanation:

m = 30kg u = 2 m/s a = -2m/s/s

Since the object has an initial velocity of 2 m/s and acceleration of -2 m/s/s

the object will come to rest in 1 second but the force applied in that one second can be calculated by:

F = ma

F = 30 * -2

F = -60 N (the negative sign tells us that the force is acting downwards)

Now, calculating the force applied on the box due to gravity

letting g = -10m/s/s

F = ma

F = 30 * -10

F = -300 N (the negative sign tells us that the force is acting downwards)

Now, calculating the total downward force:

-300 + (-60) = -360 N

Hence, a downward force of 360 N is being applied on the box and since the box did not disconnect from the rope, the rope applied the same amount of force in the opposite direction

Therefore tension on the force = 360 N