Mechanics | Relativity Answers

Calculate the apparent weight of an elevator attendant (m = 84 kg) if the elevator is accelerating downward at 2.80 m/s2.

3. A 300 m long train passed through a 500 m long tunnel. Both lengths are measured at rest. The train speeds at 4/5c from west to east through the tunnel.

In the train's reference frame:

i. What would be the length of the tunnel?

There are two passengers on the train, Ahmad who sits at the very front of train and Siti, who sits at the very rear. At the instant that the train enters the tunnel completely, Ahmad and Siti both stick out their heads up. Siti should be able to see the west end of the tunnel and Ahmad should be able see the east end of the tunnel.

ii. Will they see the ends of the tunnel simultaneously? Explain and sketch the situation.

In the tunnel's reference frame:

iii.At the instant that the train enters the tunnel completely, Ahmad and Siti stick out their heads up, will they simultaneously see the ends of the tunnel?

iv.Explain If the answer in (iii) is no, who will see the end of tunnel first? Sketch the situation.

What is projectile motion.

 A rectangular window that is 1.2 m wide and 1.8 m high has a thickness of 6.2 mm, a thermal conductivity value of 0.27 W/m/°C. The temperature inside the home is 21°C and the temperature outside the home is -4°C. Calculate the rate of heat transfer. 

An empty universe but two bodies attracted by their gravitational pull. The closer and massier they get the stronger they pull. Their speed will only increase.

How can there not be a starting distance d from which the maximum speed of the bodies does not surpasses the speed of light?

A particle of mass m has a speed v=α/x, where x is it’s

displacement. Find the force F(x) responsible.

F(x)=-mα2

/x3

 What will be the expected fringe shift on the basis of stationary ‘ether’ hypothesis in 

Michelson -Morley experiment if the effective length of each path is 8 m and wavelength of 

light used is 8000 Ả

Two blocks of mass m1 and m2 connected by a massless spring of spring constant k are placed on a smooth horizontal table. Determine the equations of motion using lagrangian mechanics.

 write the lagrangian for the system.

How much kinetic energy does a paper airplane have if its going 2m/s and has a mass of 0.01 kg? 

Dry steam at 100°C is bubbled into 500g of water originally at 20°C. What will be the temperature of the water after 30g of steam has condensed? Specific latent heat of steam is 2.26*10^6J/k, specific heat capacity of water is 4200J/Kg/k