# physics

posted by .

(c) A ladder with length L and mass m rests against a wall. Its upper end is a distance h above the ground (Figure 13.3). The center of gravity of the ladder is one-third of the way up the ladder. A fire fighter with mass M climbs halfway up the ladder. Assume that the wall, but not the ground, is frictionless. Write the sum of the forces in (i) x-direction and (ii) y-direction and (iii) the expression for the sum of the torque about the point where the ladder makes contact with the ground(O).

• physics -

(a) A 5.00 kg block is moving at vo= 6.00m/s along a frictionless, horizontal surface towards a spring with a force constant k = 500 N/m that is attached to a wall (Figure 13.5). The spring has negligible mass. Find(i) the maximum distance the spring will be compressed and (ii) the spring is compressed by no more than 0.150 m, what should be the maximum value of vo? (4 marks)

(b) A steel railroad track is 1000 m long. When its temperature is raised from -30 oto + 30 othermal expansion causes the length of the track to increase by .01%. What compressive force per unit area would be required to keep the track from expanding? (Hint: Calculate the force that would be required to compress it back to its original length. Young's modulus for steel is 2 x 1011N/m2.
(c) A hydraulic press contains 0.25m3(250 L) of oil. Find the decrease in volume of the oil when it is subjected to a pressure increase, âˆ†p = 1.6 x 107 Pa. The bulk modulus , B of oil is 5.0 x 109 Pa and its compressibility K = 1/B = 2.0 x 10-10 Pa-1.

## Similar Questions

1. ### physics

In Figure 12-6, a ladder of length L = 12 m and mass m = 46 kg leans against a slick (frictionless) wall. The ladder's upper end is at height h = 9.2 m above the pavement on which the lower end rests (the pavement is not frictionless). …
2. ### physics

A 10.9-kg monkey climbs a uniform ladder with weight w = 1.24 102 N and length L = 2.70 m as shown in the figure below. The ladder rests against the wall and makes an angle of θ = 60.0° with the ground. The upper and lower ends …
3. ### Calculus

Suppose a ladder of length 36 feet rests against a wall, and we pull the base of the ladder horizontally away from the wall. For a given distance x that we pull the ladder horizontally, let g(x) be the height of the ladder on the wall, …
4. ### Physics

A ladder, 5.0 m long, leans against a frictionless wall at a point 4.0 m above the ground. A painter is climbing up the ladder. The mass of the ladder is 12.0 kg and the mass of the painter is 60.0 kg. The ladder begins to slip at …
5. ### Physics

A 77 kg window cleaner uses a 13 kg ladder that is 7.1 m long. He places one end on the ground 3.8 m from a wall, rests the upper end against a cracked window, and climbs the ladder. He is 3.9 m up along the ladder when the window …
6. ### physics

A uniform ladder, 3 m long and weighing 130 N, placed against a smooth wall, its lower end being 1.80 m from the wall. A 700N man stands on the upper most rung of the ladder located 0.45 m from the upper end of the ladder. a.) What …
7. ### Physics

A 6m long uniform ladder which has a mass of 25kg leans with its upper end against a smoorth vertical wall and its lower end on rough horizontal ground. The base of the ladder is 3m from the wall and a man of mass 70kg is two thirds …
8. ### Physics

A 75 kg window cleaner uses a 10 kg ladder that is 7.2 m long. He places one end on the ground 4.5 m from a wall, rests the upper end against a cracked window, and climbs the ladder. He is 5.2 m up along the ladder when the window …
9. ### PHYSICS

A 75 kg window cleaner uses a 10 kg ladder that is 7.2 m long. He places one end on the ground 4.5 m from a wall, rests the upper end against a cracked window, and climbs the ladder. He is 5.2 m up along the ladder when the window …
10. ### phsics

uniform ladder 25 ft long rests against a smooth vertical wall. The ladder weighs 15 Kg. The lower end of the ladder is 15 ft from the wall. A man weighing 80 Kg climbs up the ladder until he is 20 ft from the base of the ladder, (20 …

More Similar Questions

Post a New Question