Chapter 13 - Engineering Mechanics - Dynamics Chapter 13...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Engineering Mechanics - Dynamics Chapter 13 Problem 13-1 Determine the gravitational attraction between two spheres which are just touching each other. Each sphere has a mass M and radius r . Given: r 200 mm M 10 kg G 66.73 10 12 u m 3 kg s 2 nN 1 10 9 u N Solution: F G M 2 2 r ( ) 2 F 41.7 nN Problem 13-2 By using an inclined plane to retard the motion of a falling object, and thus make the observations more accurate, Galileo was able to determine experimentally that the distance through which an object moves in free fall is proportional to the square of the time for travel. Show that this is the case, i.e., s v t 2 by determining the time t B , t C , and t D needed for a block of mass m to slide from rest at A to points B, C , and D , respectively. Neglect the effects of friction. Given: s B 2 m s C 4 m s D 9 m T 20 deg g 9.81 m s 2 Solution: W sin T + , W g a a g sin T + , a 3.355 m s 2 s 1 2 a t 2 t B 2 s B a t B 1.09 s 145 Engineering Mechanics - Dynamics Chapter 13 t C 2 s C a t C 1.54 s t D 2 s D a t D 2.32 s Problem 13-3 A bar B of mass M 1 , originally at rest, is being towed over a series of small rollers. Determine the force in the cable at time t if the motor M is drawing in the cable for a short time at a rate v = kt 2 . How far does the bar move in time t ? Neglect the mass of the cable, pulley, and the rollers. Given: kN 10 3 N M 1 300 kg t 5 s k 0.4 m s 3 Solution: v k t 2 v 10 m s a 2 k t a 4 m s 2 T M 1 a T 1.2 kN d t t k t 2 d d 16.7 m *Problem 13-4 A crate having a mass M falls horizontally off the back of a truck which is traveling with speed v . Determine the coefficient of kinetic friction between the road and the crate if the crate slides a distance d on the ground with no tumbling along the road before coming to rest. Assume that the initial speed of the crate along the road is v . 146 Engineering Mechanics - Dynamics Chapter 13 Given: M 60 kg d 45 m v 80 km hr g 9.81 m s 2 Solution: N C M g N C M g P k N C M a a P k g v 2 2 a d P k g d P k v 2 2 g d P k 0.559 Problem 13-5 The crane lifts a bin of mass M with an initial acceleration a . Determine the force in each of the supporting cables due to this motion. Given: M 700 kg b 3 kN 10 3 N a 3 m s 2 c 4 Solution: 2 T c b 2 c 2 . M g M a T M a g . ( ) b 2 c 2 . 2 c T 5.60 kN 147 Engineering Mechanics - Dynamics Chapter 13 Problem 13-6 The baggage truck A has mass m t and is used to pull the two cars, each with mass m c . The tractive force on the truck is F . Determine the initial acceleration of the truck. What is the acceleration of the truck if the coupling at C suddenly fails? The car wheels are free to roll. Neglect the mass of the wheels....
View Full Document

This note was uploaded on 04/13/2008 for the course ME 2580 taught by Professor Vandenbrink during the Spring '08 term at Western Michigan.

Page1 / 97

Chapter 13 - Engineering Mechanics - Dynamics Chapter 13...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online