3a 1‐in‐od steel tube has its outside wall surface maintained at 250 f. it is proposed to increase the rate of heat transfer by adding fins of 3/32‐in thickness and 3/4‐in long to the outside tube surface. compare the increase in heat transfer achieved by adding 12 longitudinal straight fins or circular fins with the same total surface area as the 12 longitudinal fins. the surrounding air is at 80 f, and the convective heat‐transfer coefficient is 6 btu/h ft2 f.

For general projectile motion, when the projectile is at the highest point of its trajectory, its acceleration is zero? a)the horizontal and vertical components of its velocity are zero. b) its velocity is perpendicular to the acceleration. c)the horizontal component of its velocity is zero. d)its velocity and acceleration are both zero.

Part a determine the magnitude of the x component of f using scalar notation. fx f x = nothing lb request answer part b determine the magnitude of the y component of f using scalar notation. fy f y = nothing lb request answer part c determine the magnitude of the z component of f using scalar notation. fz f z = nothing lb request answer provide feedback figure1 of 1a force vector acting on a ring attached to the ground is shown in the xyz space together with its x, y, and z components lying on the corresponding positive axes. the ring is located at the origin. force f is located in the first octant. f makes an angle of 60 degrees with its x component and an angle of 45 degrees with its y component. a force vector acting on a ring attached to the ground is shown in the xyz space together with its x, y, and z components lying on the corresponding positive axes. the ring is located at the origin. force f is located in the first octant. f makes an angle of 60 degrees with its x component and an angle of 45 degrees with its y component.

How is the gravitational force related to the distance between two objects?