# Calculate the magnitude of the tension force in the rope

1. Feb 18, 2004

### psruler

Can anyone help me on two problems of my hw?

1) A tow rope is used to pull a 1050-kg along a level road, initially accelerating it from rest at 1.50m/s^2 for a duration of 12.0seconds. Calculate the magnitude of the tension force in the rope during this acceleration.(ignore friction in the problem)

My answer was 394N but i want to make sure if that was correct.

2) As a stoplight is approached, the person riding in the towed car applies the brakes and brings it to a stop in an additional 5.00s. Calculate the magnitude of the force of the brakes on the car, assuming the brakes are applied evenly so that the deceleration is constant.

2. Feb 18, 2004

### NateTG

Regarding question 1:

This is clearly an "F=ma" question. A mass of 1050 KG and an acceleration 1.5 m/s^2should give a force of at least 1500N

Question 2:
There's a bunch of ways to do this one. One of the easiers ways is to use v=at to find the starting velocity, and then the force in a similar fashion. Clearly the force here is larger than the force for question 1.

3. Feb 18, 2004

### psruler

Ok, I got the initial velocity for ques.2 and where do I go from there?

4. Feb 19, 2004

### NateTG

The change in velocity is equal to the acceleration multiplied by the time. You know the change in velocity, and the time, so that should give you the acceleration.

5. Feb 19, 2004

### psruler

wouldn't that give me an acceleration of 1.5 again?

6. Feb 19, 2004

### psruler

Ok i got it. thanks NateTG for your help!