The magnitude J of the current density in a certain wire with a circular cross section of radius R=2.02 mm is given by J = (3.03 × 108)², with Jin amperes per square meter and radial distance r in meters. What is the current through the outer section bounded by r = 0.902R and r= R? Number Units

A 1200 kg car is traveling towards a hill at a speed of 25.3 m/s when suddenly the car runs out of gas to what vertical hight in meters is the car able to coast up the hill before coming to a stop

If you push a 3Kg book across your desk at a constant speed of 2 m/s with a force of 7N what is the net force that acts on the book? NO O O 7N O 21N O 42N 5 7 8. 9 10 11

(2) The box with M = 40kg shown below is being pulled by two pulleys exerting forces F₁ = 400 N (0₁ = 60°) and F₂ = 200 N (0₂= 15°) up an incline with an angle 0₁ = 30°. If the uk = 0.15. What is the acceleration of the box? Would the F₁ or F₂ be enough alone to pull the box up if the other pulley would stop working?

Question 4

Question #2 of the attachment.  Thank you in advance

Problem 4: Speed deamplifier. In the figure above on the right, block 1 of mass m1 slides along an x-axis on a frictionless floor at speed 4 m/sec.Then it undergoes a one-dimensional elastic collision with stationary block 2 of mass m2 = 2m1. Next, block 2 undergoes a one-dimensional elastic collision with stationary block 3 of mass mz = 4m1. What then is the speed of block 3? Answer: 16 m/sec or 1.78 m/sec.