A steel bar 2.5 cm square and 7.5 cm long is initially at a temperature of 250?C. It is immersed in a tank of oil maintained at 30?C. The heat-transfer coefficient is 570 W/m2 Â· ?C. Calculate the temperature in the center of the bar after 3 min. Explain your answer in clear detail, show your work and write down all steps leading up to your final answer .... Read More

The 4-in.-radius wheel shown rolls to the left with a velocity of 45 in./s. Knowing that the distance AD is 2.5 in., determine the velocity of the collar and the angular velocity of rod AB when (a) ÃŸ = 0, (b) ÃŸ = 90o. .... Read More

5/110 Determine the force and moment reactions at A for the beam which is subjected to the load combina- tion shown. 5/113 Determine the force and moment reactions at the support A of the built-in beam which is subjected to the sine-wave load distribution. 5 kip/ft Problem 5/110 Problem 5/113 .... Read More

During World War II, tritium (3H) was a component of fluorescent watch dials and hands. Assume you have such a watch that was made in January 1944. If 17% or more of the original tritium was needed to read the dial in dark places, until what year could you read the time at night? (For 3H, half life= 12.3 yr.) .... Read More

The slender bar is moving in general plane motion with the indicated linear and angular properties. Locate the instantaneous center of zero velocity and determine the velocities of points A and B. .... Read More

Find the vertical component of force in the metal at the base of the spherical dome shown when gage A reads 5 psig. Indicate whether the metal is in compression or tension. The specific gravity of the enclosed fluid is 1.5. The dimension L is 2 ft. Assume the dome weighs 1000 lbf. Explain your answer in explicit details, and list all steps leading up to your final answer. .... Read More

The grooved drums in the two systems shown are identical. In both cases, (a) and (b), the system is at rest at time t = 0 Determine the angular velocity of each grooved drum at time t = 4 s. Neglect friction at the pivot O. .... Read More

2/43 As a trailer is towed in the forward direction, the force F = 120 lb is applied as shown to the ball of the trailer hitch. Determine the moment of this force about point O. Problem 2/45 F = 120 lb 1.25Â¢Â¢ Problem 2/43 .... Read More

The bracket BCD is hinged at C and attached to a control cable at B. For the loading shown, determine (a) the tension in the cable, (b) the reaction at C. .... Read More

3/1 The 50-kg homogeneous smooth sphere rests on the 30Â° incline A and bears against the smooth vertical wall B. Calculate the contact forces at A and B. 3/4 The uniform beam has a mass of 50 kg per meter of length. Determine the reactions at the supports. y Problem 3/4 Problem 3/1 .... Read More