A light spring obeys Hooke's law. The spring's unstretched length is 33.0 cm. One end of the spring is attached to the top of a doorframe and a weight with mass 7.75 kg is hung from the other end. The final length of the spring is 45.5 cm. (a) Find its spring constant (in N/m). 0.06076 N/m (b) The weight and the spring are taken down. Two people pull in opposite directions on the ends of the spring, each with a force of 190 N. Find the length (in m) of the spring in this situation. m (c) What If? What would be the length (in m) of the spring if it were now attached to the vertical portion of the doorframe and stretched horizontally by a single person exerting a force of 190 N? m

A light spring obeys Hooke's law. The spring's unstretched length is 33.0 cm. One end of the spring is attached to the top of a doorframe and a weight with mass 7.75 kg is hung from the other end. The final length of the spring is 45.5 cm. (a) Find its spring constant (in N/m). 0.06076 N/m (b) The weight and the spring are taken down. Two people pull in opposite directions on the ends of the spring, each with a force of 190 N. Find the length (in m) of the spring in this situation. m (c) What If? What would be the length (in m) of the spring if it were now attached to the vertical portion of the doorframe and stretched horizontally by a single person exerting a force of 190 N? m

Physics for Scientists and Engineers: Foundations and Connections

1st Edition

ISBN:9781133939146

Author:Katz, Debora M.

Publisher:Katz, Debora M.

Chapter14: Static Equilibrium, Elasticity, And Fracture

Section: Chapter Questions

Problem 81PQ: A horizontal, rigid bar of negligible weight is fixed against a vertical wall at one end and...

See similar textbooks

Similar questions

A horizontal, rigid bar of negligible weight is fixed against a vertical wall at one end and supported by a vertical string at the other end. The bar has a length of 50.0 cm and is used to support a hanging block of weight 400.0 N from a point 30.0 cm from the wall as shown in Figure P14.81. The string is made from a material with a tensile strength of 1.2 108 N/m2. Determine the largest diameter of the string for which it would still break. FIGURE P14.81
A lightweight spring with spring constant k = 225 N/m is attached to a block of mass m1 = 4.50 kg on a frictionless, horizontal table. The blockspring system is initially in the equilibrium configuration. A second block of mass m2 = 3.00 kg is then pushed against the first block, compressing the spring by x = 15.0 cm as in Figure P16.77A. When the force on the second block is removed, the spring pushes both blocks to the right. The block m2 loses contact with the springblock 1 system when the blocks reach the equilibrium configuration of the spring (Fig. P16.77B). a. What is the subsequent speed of block 2? b. Compare the speed of block 1 when it again passes through the equilibrium position with the speed of block 2 found in part (a). 77. (a) The energy of the system initially is entirely potential energy. E0=U0=12kymax2=12(225N/m)(0.150m)2=2.53J At the equilibrium position, the total energy is the total kinetic energy of both blocks: 12(m1+m2)v2=12(4.50kg+3.00kg)v2=(3.75kg)v2=2.53J Therefore, the speed of each block is v=2.53J3.75kg=0.822m/s (b) Once the second block loses contact, the first block is moving at the speed found in part (a) at the equilibrium position. The energy 01 this spring-block 1 system is conserved, so when it returns to the equilibrium position, it will be traveling at the same speed in the opposite direction, or v=0.822m/s. FIGURE P16.77
Use the data in Table P16.59 for a block of mass m = 0.250 kg and assume friction is negligible. a. Write an expression for the force FH exerted by the spring on the block. b. Sketch FH versus t.
A uniform wire (Y = 2.0 1011 N/m2) is subjected to a longitudinal tensile stress of 4.0 107 N/m2. What is the fractional change in the length of the wire?
A vibration sensor, used in testing a washing machine, consists of a cube of aluminum 1.50 cm on edge mounted on one end of a strip of spring steel (like a hacksaw blade) that lies in a vertical plane. The strips mass is small compared with that of the cube, but the strips length is large compared with the size of the cube. The other end of the strip is clamped to the frame of the washing machine that is not operating. A horizontal force of 1.43 N applied to the cube is required to hold it 2.75 cm away from its equilibrium position. If it is released, what is its frequency of vibration?
A spring (k888 N/m) is hanging from the ceiling of an elevator, and a 7.1 kg object is attached to the lower end. By how much does the spring stretch (relative to its unstrained length) when the elevator is accelerating upward at a 0.74 m/s²?
the drawing shows a 150 kg crate hanging from one end of steel bar (S= 8.1 x10^10 n/m^2) The length of the bar is 0.428 m and its cross-sectional area is 7.94 x 10 ^-4 m^2. Neglect the weight of the bar itself and determine (a) the shear stress on the bar and (b) the vertical deflection deltaY of the right end of the bar.
A cubic meter (1.00 m^3) of water with bulk modulus 2.2x10^9 Pa is collected from the ocean's surface, where the atmospheric pressure is 1.0x10^5 Pa. It is brought 10.9 km below the surface in a container that can freely expand/contract, to the bottom of the Marianas Trench where the pressure 1.16x10^8 Pa. What is the volume of the water at this depth?
A copper wire of length 6.1 m, cross sectional area 1.7 7 * 10^-6 * m^2 Young's modulus 11 * 10^10 N/(m ^ 2) has a 571 kg load hung on it. What is its increase in length? (g = 9.8 m/s^2)
Young's modulus of iron rod is 21 × 1010 N/m2. A force of 7.0 × 105 N is applied to a 1.5-m length of iron of cross sectional area 0.25 m2. By what amount does the iron stretch? 3.9 × 10^–3 m 2.0 × 10^–5 m 3.1 × 10^–2 m 9.7 × 10^–4 m
A solid copper cube has an edge length of 85.5 cm. How much stress must be applied to the cube to reduce the edge length to 85.0 cm? The bulk modulus of copper is 1.4*1011 N/m2.
The pressure increases by 1.0 x 104 N/m2 for every meter of depth beneath the surface of the ocean. At what depth does the volume of a Pyrex (bulk modulus 2.6 x 1010 N/m2) glass cube, 6.8 x 10-2 m on an edge at the ocean's surface, decrease by 7.5 x 10-10 m3?