A 3.61 g bullet moving at 744 m/s penetrates a tree to a depth of 2.03 cm . Use energy considerations to find the average frictional force that stops the bullet. Answer in units of N.

Would corn syrup, molasses, or pancake syrup make a good lubricant in a car engine? explain your answer.

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.

What was the approximate temperature of the universe at an age of 1015 s?