Concept explainers
On February 15, 2013, Asteroid 2012 DA14 passed within 17,200 miles [mi] of the surface of the Earth at a relative speed of 7.8 kilometers per second [km/s]. This is considerably closer than the orbit of geosynchronous satellites (26,200 miles). This is the closest recorded approach of an object this large. The asteroid 2012 DA14 was estimated to have a diameter of 30 meters [m] and a specific gravity of 3. If 2012 DA14 had hit the Earth, what is the total amount of energy that would have been released (i.e., what was the kinetic energy of the asteroid)? Express your answer in megatons [Mton]. One megaton is the energy released by one million metric tons of TNT explosive. A metric ton equals 1000 kilograms [kg], and the explosive energy of TNT is 4184 joules per gram [J/g].
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
Thinking Like an Engineer: An Active Learning Approach (4th Edition)
- The rotating blade of a blender turns with a constant angular acceleration 1.50 [rad/s^2].a. How much time does it take to reach an angular velocity of 36.0 [rad/s^2] starting from rest? b. Through how many revolutions does the blade turn in this time interval? c. What are the tangential acceleration and tangential speed of an ant sitting on the blade 10.0 cm from the axis of rotation during the end of this interval? d. What is the moment of inertia of the ant if its mass is 10.0 g? e. What is the rotational kinetic energy of the ant?arrow_forwardA freezer of dimensions 4 m wide, 6 m long and 3 m high is under construction. The walls and ceiling are composed of 1.7 mm stainless steel (k = 15 W / [m ° C]), 10 cm thick foam insulation (k = 0.036 W / [m ° C]), a specific thickness of corkboard (k = 0.043 W / [m ° C]), and 1.27 cm thick wood (k = 0.104 W / [m ° C]). The inside of the freezer is maintained at -30 ° C. The ambient air outside the freezer is 32 ° C. The convective heat transfer coefficient is 5 W / (m K) on wooden walls and 2 W / (m² K) on stainless steel surfaces. If the outside air has a dew point of 29 ° C, calculate the thickness of the corkboard insulation that will prevent moisture condensation on the outside walls of the freezer. Calculate the heat transfer rate through the walls and ceiling of this freezer. Ignore heat transfer from floors and corners of buildings. a. Thickness of corkboard insulation = cm. b. Heat transfer rate through walls and ceiling = watts.arrow_forwardA freezer with dimensions of 4 m wide, 6 m long and 3 m high is under construction. The walls and ceiling are composed of 1.7 mm stainless steel (k = 15 W / [m ° C]), 10 cm thick foam insulation (k = 0.036 W / [m ° C]), a specific thickness of corkboard (k = 0.043 W / [m ° C]), and 1.27 cm thick wood (k = 0.104 W / [m ° C]). The inside of the freezer is maintained at -30 ° C. The ambient air outside the freezer is 32 ° C. The convective heat transfer coefficient is 5 W / (m K) on wooden walls and 2 W / (m² K) on stainless steel surfaces. If the outside air has a dew point of 29 ° C, calculate the thickness of the corkboard insulation that will prevent moisture condensation on the outer walls of the freezer. Calculate the heat transfer rate through the walls and ceiling of this freezer. Ignore heat transfer from floors and corners of buildings. a. Thickness of corkboard insulation = cm. b. Heat transfer rate through walls and ceilings = watts.arrow_forward
- A freezer with dimensions of 4 m wide, 5 m long and 3 m high is under construction. The walls and ceiling are composed of 1.7 mm stainless steel (k = 15 W / [m ° C]), 10 cm thick foam insulation (k = 0.036 W / [m ° C]), a specific thickness of corkboard (k = 0.043 W / [m ° C]), and 1.27 cm thick wood (k = 0.104 W / [m ° C]). The inside of the freezer is maintained at -35 ° C. The ambient air outside the freezer is 32 ° C. The convective heat transfer coefficient is 5 W / (m K) on wooden walls and 2 W / (m² K) on stainless steel surfaces. If the outside air has a dew point of 29 ° C, calculate the thickness of the corkboard insulation that will prevent moisture condensation on the outer walls of the freezer. Calculate the heat transfer rate through the walls and ceiling of this freezer. Ignore heat transfer from floors and corners of buildings. a. Thickness of corkboard insulation = Answer cm b. Heat transfer rate through walls and ceiling = Answer wattarrow_forwardA steel ball of mass 0.50 kg, moving with a velocity of 2.0 m/s [E], strikes a second ball of mass 0.30 kg, initially at rest. The collision is a glancing one, causing the moving ball to have a velocity of 1.5 m/s [30° N of E] after the collision. Determine the velocity of the second ball after the collision.arrow_forwardThe rotating blade of a blender turns with a constant angular acceleration 1.50 [rad/s^2].a. How much time does it take to reach an angular velocity of 36.0 [rad/s^2] starting from rest? Through how many revolutions does the blade turn in this time interval? b. What are the tangential acceleration and tangential speed of an ant sitting on the blade 10.0 cm from the axis of rotation during the end of this interval? c. What is the moment of inertia of the ant if its mass is 10.0 g? What is the rotational kinetic energy of the ant?arrow_forward
- A freezer of dimensions 4 m wide, 6 m long and 3 m high is under construction. The walls and ceiling are composed of 1.7 mm stainless steel (k = 15 W / [m ° C]), 10 cm thick foam insulation (k = 0.036 W / [m ° C]), certain thickness of corkboard (k = 0.043 W / [m ° C]), and 1.27 cm thick wood (k = 0.104 W / [m ° C]). The inside of the freezer is maintained at -30 ° C. The ambient air outside the freezer is 32 ° C. The convective heat transfer coefficient is 5 W / (m K) on wooden walls and 2 W / (m² K) on stainless steel surfaces. If the outside air has a dew point of 29 ° C, calculate the thickness of the corkboard insulation that will prevent moisture condensation on the outer walls of the freezer. Calculate the rate of heat transfer through the walls and ceiling of this freezer. Ignore heat transfer from floors and corners of buildings. a. Thickness of corkboard insulation = Answercm. b. Heat transfer rate through walls and ceilings = Answerwatt.arrow_forwardA 37.3 kW [50 HP] gasoline tractor is used to operate a pull-type sprayer. The tractor’s list price was $6,500 and it is used an average of 400 hours per year. The sprayer’s list price is $1,500 and it is used 100 hours per year. The sprayer has a 9.2 m [30 ft.] boom and operates at 8 km/hr. [5 mi/hr.] with a field efficiency of 60%. Fuel cost 15 ¢/L [56.8 ¢/gal] and the labor cost is $3.00/hr. What are the total hourly cost, the cost per hectare, and the cost per acre sprayed? The tractor is expected to be owned for 15 years and the sprayer for 10 years.arrow_forward(The complete question is in the picture) Initially, a warehouse worker pushes a 55 [N] box on a flat, rough, horizontal surface just enough so that the box moves with a constant velocity of 4.2 [m/s].However, he gets tired and suddenly stops pushing the box. With the coefficient of kineticfriction between the box and the surface equal to 0.45, how long does it take for the box tostop? A. 0.95 [s]B. 2.1 [s]C. 4.4 [s]D. 9.3 [sarrow_forward
- Feeding Rate (R) [g/h] 6 5 1 0 A B 0 1 U 2 3 E D F 4 5 6 7 8 9 Time (t) [h] 10 11 12 13 14 The feeding rate in grams per hour is displayed as a function of time in hours [h] for a bioreactor. Select the phrase that makes the following sentences true. Between points C and D, the feeding rate [Select ] Between points D and E, the feeding rate [Select] The mass of feed in grams [g] added to the bioreactor between points F and G is [Select ] The mass of feed added to the bioreactor between points E and F is zero The mass of feed added to the bioreactor between points H and I is [Select] grams [g].arrow_forward27. What the tank? Consider the shown pressurized wa- ter tank (PH20 is 5.00 times atmospheric pressure, and A's cross- A 997 (kg/m³)). The pressure at A sectional area is 3.31 times that of B. What is the 50 m speed of the exiting water? В 20 m A. 2008 [m/s] С. 39.3 [m/s] B. 2080 [m/s] D. 40.0 [m/s] 28. Grave tE! Consider four identical objects with mass m held at the corners of a square with each side of a. Ob- ject x with same mass m is placed at the midpoint of the bottom side of the square as shown in the figure. What is the magnitude of the net gravitational force on object x а due to all the masses? 8GM2 A. 5/5a? В. 16Gm? 5V5a2 а С. 4Gm? 5/5a2 D. zero 29. CharTRUEse. Which is of the following is always TRUE about a particle in simple harmonic motion? A. The acceleration of the particle is independent of its mass. B. The position of the particle can always be determined using constant acceleration kinematic equations. C. The force on the particle acts in the same direction as its…arrow_forwardAn airplane flies 250 km [E 250N], and then flies 280 km [S 130W]. Using components, calculate the airplane’s totaldisplacement.arrow_forward
- Elements Of ElectromagneticsMechanical EngineeringISBN:9780190698614Author:Sadiku, Matthew N. O.Publisher:Oxford University PressMechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSONThermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
- Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEYMechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage LearningEngineering Mechanics: StaticsMechanical EngineeringISBN:9781118807330Author:James L. Meriam, L. G. Kraige, J. N. BoltonPublisher:WILEY