If a person with mass 70.0kg, standing still, throws an object with mass 5.0kg at 50.0m/s, what will be the recoil velocity of the person, assuming he is standing on a frictionless surface? A. −3.6m/s

B. 0m/s

C. 3.6m/s

B. 50.0m/s

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 740 n/m. it is initially at rest on an inclined plane that is at an angle of theta= 26 with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is uk = 0.17. in the initial position, where the spring is compressed by a distance of d = 0.16 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. the block's initial mechanical energy is 9.472 j.b. if the spring pushes the block up the incline, what distance l in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.

Certain bacteria (such as aquaspirillum magnetotacticum) tend to swim toward the earth’s geographic north pole because they contain tiny particles, called magnetosomes, that are sensitive to a magnetic field. if a transmission line carrying 100 a is laid underwater, at what range of distances would the magnetic field from this line be great enough to interfere with the migration of these bacteria? (assume that a field less than 5% of the earth’s field would have little effect on the bacteria. take the earth’s field to be 5.0 * 10-5 t, and ignore the effects of the seawater.)

Question 1(multiple choice worth 2 points) in order to be considered work, the components that must be present are • a force and a movement in the same direction as the force an action which causes movement and an opposite reaction an action which causes no movement or reaction a force and a movement in the opposite direction of the force