# Homework Help: Physics Questions

1. Oct 16, 2007

### NJCarter15

Physics Questions!!

1. The problem statement, all variables and given/known data
Gloria is pulling her baby in his sled. The baby and sled have a mass of 75 kg. If she is holding the rope to the sled at a 45o angle and she wants to accelerate at 0.5 m/s2 how much force does she need to exert?

2. Relevant equations
d = v x t vavg = ½ (vf + vi) vf = at + vi
a = (vf - vi) / t d = vi t+ ½ at 2 vf2 = vi2 + 2ad
d = (vf2 - vi2)/2a F = ma g = acceleration due to gravity = -10 m/s2; Pressure = N/m2 = Pa

3. The attempt at a solution

2. Oct 16, 2007

### Staff: Mentor

You must show us your attempt at a solution before we can help you. That's one of the PF rules (see the "Rules" link at the top of the page).

So how would you start this problem?

3. Oct 16, 2007

### NJCarter15

Well my attempt would be as followed:

Since I know the mass of 75kg and the acceleration (.5m/s2) I now know Fnet in the equation Fnet = Ftension + Fg. Now how do I incorporate an angle into this problem?

4. Oct 16, 2007

### qspeechc

Resolve the force so everything is along the same line.

5. Oct 16, 2007

### NJCarter15

Yes but how would I go about solving the problem?

6. Oct 16, 2007

### qspeechc

And then you have one force that is multiplied by some trig function, equal to some other forces. You have enough information to solve this problem. Show us some of your working out.

7. Oct 16, 2007

### NJCarter15

I have force due to gravity which is mg (75kg)(-10m/s^2). Do I solve for that and then use trig. I do not know?

8. Oct 16, 2007

### malty

No, you need to work out the component of the force due to gravity that is acting on the sled. As was already said, resolve the components to one line.

Draw a diagram of exactly what is happening and what you think the forces acting upon it are, and if possible show us this diagram.