To practice problem-solving strategy 27.1: magnetic forces. a particle with mass 1.81×10−3 kg and a charge of 1.22×10−8 c has, at a given instant, you can check your result by comparing its magnitude to the magnitude the acceleration would have if the particle's velocity had the same magnitude but it was perpendicular to the magnetic field. find the value of the expression

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arranged side by side so that they are parallel to each other. when you push the platform, you compress the springs. you do an amount of work of 79.0 j when you compress the springs a distance of 0.230 m from their uncompressed length. (a) what magnitude of force must you apply to hold the platform in this position? (b)how much additional work must you do to move the platform a distance 0.230 m farther? (c) what maximum force must you apply to move the platform a distance 0.230 m farther?