Recent content by lim

oooh, I had a feeling it had something to do with unit conversions, but the E threw me off. I guess I'm used to seeing 10^x. Thanks for pointing it out Astronuc.

Homework Statement A car does 6.48E+4 J of work in traveling 2.92 km at constant speed. What was the average retarding force (from all sources) acting on the car? 22.2 N Homework Equations F= w/d The Attempt at a Solution F= w/d 6.48/ 2.92= 2.22 N ?

Homework Statement How much work must be done to stop a 1100 kg car traveling at 118 km/hr? Homework Equations Ei + W= Ef KE= 1/2mv^2 The Attempt at a Solution KE= 1/2mv^2 118kmx1000m/360s= 327.78 327.78^2= 107437.76 107437.76x1100= 118181537.9 118181537.9/2 =...

Just for understanding, Why isn't the value negative or why would it be the magnitude? Is it because friction is slowing down so it would always be a negative number?

It meant sigmaF=ma/mg. I put w, because w=mg. The magnitude of F, force was 3.796(2090)=7933.64 N. Is my method incorrect? I was trying to find the acceleration and use F=ma, and then I use (mu)= F/(mg).

Homework Statement You are driving a 2090 kg car at a constant speed of 22.2 m/s along an icy, but straight and level road. While approaching a traffic light, it turns red. You slam on the breaks. Your wheels lock, the tires begin skidding, and the car slides to a halt in a distance of 64.9...

Well, we submit our answers online and it only tells us if it's right or wrong. But -43.85 was also incorrect, so should I be adding like 90° or 180° to it? As if it was trying to find the angle around it, and not the angle itself?

Oh, it also said to find the angle with respect to the x -axis, if that clarifies. So if it is in the fourth quadrant the angle would be negative?

Homework Statement What is the y-component of a vector in the x-y plane whose magnitude is 86.4 and whose x-component is 62.3? 59.9 Homework Equations a^2 + b^2 = c^2 Sin-1= Vy/|v| The Attempt at a Solution a^2 + b^2 = c^2 And 59.9 was right for that, but i used Sin-1= Vy/|v|...

I'm confused about part three. They give me an acceleration(-2.0 m/s^2) and I have the mass (57 kg), but how do I tie in the velocity(10m/s)?

Homework Statement A 57.0 kg girl weighs herself by standing on a scale in an elevator. What is the force exerted by the scale when the elevator is descending at a constant speed of 10 m/s? What is the force exerted by the scale if the elevator is accelerating downward with an acceleration...

Ohh. So, the tension of the upper cord is [SIZE="2"]Tu = ma + W + [SIZE="2"]Tl, so [SIZE="2"]Tu = 0 + 38.2 + 38.2N, [SIZE="2"]Tu = 76.44 N. Thanks!

Homework Statement One 3.90 kg paint bucket is hanging by a massless cord from another 3.90 kg paint bucket, also hanging by a massless cord, as shown in figure below. If the buckets are at rest, what is the tension in the lower cord? What is the tension in the upper cord? Homework...

Homework Statement Consider this situation: A police officer arrives at the scene of an accident and finds a load of straw bales partly on the back of a pickup truck and partly on the hood of a Jaguar sedan. Both vehicles are facing in the same direction. The pickup is in front of the...

Homework Statement On some strange planet you find that a 9.2 kg object falls downward 27.4 meters in 6.2 seconds. What is the magnitude of the acceleration due to gravity on this planet? How much does the object weigh on this planet? How much would it weigh back on earth? Homework...