Mohammad

A heat exchanger is rated at 10 MW and is supplied with water at 20oC. The exchanger heats the water to 100oC at which point it is turned into dry steam. The heat exchanger supplies dry steam at 2 kg/s. If the specific heat capacity of water is 4.19 KJ/kg/K and the specific latent heat of vaporisation is 2.25 MJ/kg.

Determine:

a) The thermal Energy required to heat the water from 20oC to 100oCwater

b) The Thermal Energy required to change the state of 2 kg/s of water at 100oC to steam at 100oC

c) The Total Heat supplied to change the water to steam

d) The thermal efficiency of the heat exchanger

A 3m long steel bar is heated from 200C to 3500C. The modulus of elasticity of the bar is 205 GPa. The coefficient of linear expansion for steel is 15x10-6 per oC.

i) Calculate the expansion due to the increase in temperature.

ii) Calculate the thermal stress induced in the bar if the bar is fixed at both ends.

Any answer is greatly appreciated. thank you.

ii) In order to calculate the density of an irregular (difficult to measure the dimensions for volume) shaped body in the lab, you are given a Balance, a hydrostatic bench, a beaker of fresh water and a box of weights to find the mass of the irregular shaped body in air and also the mass when fully immersed in water You found the mass in air to be 212.5g and when fully submerged in water, the mass was found to be 194.24g Find the density of the body?

i) A density flask is accurately weighed empty and its mass is 60.291g.lt is then carefully filled with oil up to the engraved volume on the flask being 99.98ml. The flask is re-weighed and the total mass is found to be 155.158 g. Calculate the density of the oil.

ii) In order to calculate the density of an irregular (difficult to measure the dimensions for volume) shaped body in the lab, you are given a Balance, a hydrostatic bench, a beaker of fresh water and a box of weights to find the mass of the irregular shaped body in air and also the mass when fully immersed in water You found the mass in air to be 212.5g and when fully submerged in water, the mass was found to be 194.24g Find the density of the body

iii) Evaluate the methods you used to determine the density of a solid material and the density of a liquid in the first two questions and also that of a body that floats in water.

I've done part i but I don't understand the rest. Can someone please help.

can't find much on this. someone help.

i) A density flask is accurately weighed empty and its mass is 60.291g.lt is then carefully filled with oil up to the engraved volume on the flask being 99.98ml. The flask is re-weighed and the total mass is found to be 155.158 g. Calculate the density of the oil.

ii) In order to calculate the density of an irregular (difficult to measure the dimensions for volume) shaped body in the lab, you are given a Balance, a hydrostatic bench, a beaker of fresh water and a box of weights to find the mass of the irregular shaped body in air and also the mass when fully immersed in water You found the mass in air to be 212.5g and when fully submerged in water, the mass was found to be 194.24g Find the density of the body

iii) Evaluate the methods you used to determine the density of a solid material and the density of a liquid in the first two questions and also that of a body that floats in water.

if you can answer any of the questions, it will be much appreciated.

Im currently an engineering student but college is really stressing me out. i am always grateful for the position i am now but i really don't know if i want to be an engineer for the rest of my life. i tend to get bad anxiety from thinking about my future too much.

The crash structure of a simple race car chassis is made up of a tubular space frame design. Whilst each of the members of the space frame carries a load, one of the members is subjected to a greater load than all other members. The frame is manufactured from steel with a Young’s’ Modulus E of 200 GPa.

The member carrying the greatest load is subjected to a load of 1750N acting axially through the member. The space frame is made up of the same steel tube with an inner diameter of 20 mm and an outer diameter of 30 mm.

b. Calculate the direct stress in the member.

c. Calculate the Strain on this Strut.

d. If the original length of the member carrying the greatest load is 550mm, calculate the extension of the component when it is subjected to the load stated in part (a).

Three plates are held together by two cylindrical rivets, as shown in figure 1. If a direct pull of 5 kN is applied between one plate and the other two as shown.

ii. Calculate the diameter of each rivet if the shear stress, not to exceed 40N/mm2.

A Pile Driver of mass 50kg is raised to a height of 4m above the Pile of mass 6 kg, and then is allowed to fall freely onto the Pile on the ground. The pile and the Pile driver travel into the ground a depth of 24 cm after impact, without rebounding.

b. Determine the values of potential and kinetic energy (of the pile driver)

i. Before it starts to fall,

ii. When it has fallen by 1m

iii. When it strikes the pile?

c. Initial velocity of the pile and the driver after impact.

d. Also calculate the retarding force causing the Pile and the pile driver to come to rest.

A motor vehicle weighing 2250kg has its hand-brake released at the top of a ramp which is 10m long and is at an angle of 10 degrees to the horizontal. Find the velocity of the vehicle the instant it reaches the bottom of the ramp. There are two methods of doing this. The energy method and the linear motion method.

need this for my homework and i really don't understand it. perhaps there are some people who understands physics or mechanics.

1) a car hauls a trailer at a constant velocity of 100km/h when exerting a steady pull of 500N.

a) whats the work done in 20 mins

b) the power required

2)Calculate the work done and the power dissipated in a moving body along a horizontal surface 15 metres at a constant velocity, When the only applied force is equal to the weight of the body the movement lasts 10 seconds and the mass of the body is 20 kilograms

3) Calculate the work done and the power dissipated for a mass of weight 500n to be horizontally moved at a constant velocity for 160 metres when the whole movement lasts 20 seconds.