Recent content by Bengalfan985

The equation you used is only for when the spring is at rest, Δx is calculated from the equilibrium point. You're work would be correct if they said the spring was stretched 1.5 meters from it's equilibrium point. Think about a spring that is as rest compared to a similar one that is stretched...

Wouldn't y1 = 1? Otherwise y2 = -2. But g would be positive as well, since you made both of them negative, the negatives canceled out. Other than that, my work and answer is the same as yours. Eint is the work done by friction to bring the runner to rest. All of the energy at Et1 is converted...

You're right, thanks! 326 would be the correct answer. With a constant force, if he travels 10 meters, he can't start from rest (he'd start with a velocity of -3.1m/s). If he starts from rest, he can't travel only 10 meters (he traveled 29.8 meters).

Homework Statement A boy pulls his brother in a wagon (total mass of 35kg). He exerts a force of 72 N at an angle of 45° above the horizontal. a) How much power is he using if he walks 10 meters in 6.4 seconds? b) How fast will his brother be going after 6.4 seconds c) What is the impulse...