A sled with a mass of 40kg is pulled along flat, snow-covered ground. The static friction coefficient is 0.40, and the kinetic friction coefficient is 0.20. A. What does the sled weigh?
B. What force will be needed to start the sled moving?
C. What force is needed to keep the sled moving at a constant velocity?
D. Once moving, what total force must be applied to the sled to accelerate it at 3.0m/s^2?

Which of the following are risk factors for emphysema ? correct answer : a and and c          good luck and have a nice benevolentpuppy day! : )

Answerthe energy required is 1.60 × 10⁻¹⁸ j, to three significant figures.explanationwe define electric potential as the ratio electric potential energy to the charge,    then the following gives us the potential difference,      the formula  may be on your formula sheet.the change in electric potential energy would be the energy that would needed to move it from point a to point b. solving for that, we get    using q = 8.00  × 10⁻¹⁹ c and  δv = 2.00 v, we get    the energy required is 1.60 × 10⁻¹⁸ j, to three significant figures.