It is found that when a particular object with a mass of 0.41 kg is released from rest while immersed within a certain substance, the coefficient of proportionality regarding the resistive force is 0.621 kg/s. What is the magnitude of the resistive force that acts on this mass 1.49 s after being released? Let the resistive force be given by R = -bv  (Assume that the gravitational force also acts)

A circular hoop of radius R made of thin wires of different linear densities. Half hoop has density u1 and the other half u2.  When a point mass m is placed at the center of the hoop point O, find the net force that the hoop acts on m

a)A block of mass m = 170 kg rests against a spring with a spring constant of k = 680 N/m on an inclined plane which makes an angle of θ degrees with the horizontal. Assume the spring has been compressed a distance d from its neutral position. b)Enter an expression for the normal force, FN, that the plane exerts on the block (in the y-direction) in terms of defined quantities and g.  c)Denoting the coefficient of static friction by μs, write an expression for the sum of the forces in the x-direction just before the block begins to slide up the inclined plane. Use defined quantities and g in your expression  d) Assuming the plane is frictionless, what will the angle of the plane be, in degrees, if the spring is compressed by gravity a distance 0.1 m?  e) If the velocity at the bottom is the same as the velocity at the top from part (a), what is the child's apparent weight, in newtons, at the very bottom of the path?

Many physical properties, such as force and mass, cannot be measured directly. Rather, some other physical property is measured and the desired physical property is computed from the results. For example, a bathroom scale does not actually measure mass or "weight," but rather the compression distance of a spring. The numerical values on the scale are calibrated from the compression distance using basic physics principles such as Newton's second law. Coefficients of friction cannot be measured directly. In this problem, we are going to learn how we can indirectly measure the coefficient of kinetic friction between two surfaces by directly measuring the expansion of a spring. Consider a 5.45 kg5.45 kg block that is dragged by a spring on a (relatively) frictionless horizontal surface at constant velocity. Suppose the block reaches a rough patch and the spring stretches by 5.25 cm5.25 cm. Compute the coefficient of kinetic friction ?μ between the block and the rough patch if the spring…