Why is heat engine 100 percent efficient

Experiment scenario 2: a biology student wants to conduct a study of how the amount of food affects the weight gain for mice. i have set up four cages with a mouse in each cage. fill in the boxes that would allow the biology student to complete the study correctly

The magnitude of the magnetic field at a certain distance from a long, straight conductor is represented by b. what is the magnitude of the magnetic field at twice the distance from the conductor? a. at twice the distance, the magnitude of the field is 4b.b. at twice the distance, the magnitude of the field is 2b.c. at twice the distance, the magnitude of the field is b/2.d. at twice the distance, the magnitude of the field is b/4.e. at twice the distance, the magnitude of the field remains equal to b.

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.