Physics Answers

a cylindrical tank of 2m diameter is laid with its axis horizontal and is filled with water just to the top,the force on one of its end plate in kn is

Hypervelocity bullet used in 0.22 long rifle usually weigh around 2.1 g and can have a speed of 550 m/s. what must be the speed of a 75 kg man to match the momentum of this bullet?

Three charged particles are arranged in a line as shown in figure below. Charge A = -5 μC, charge B = +10 μC and charge C = -12 μC. Calculate the net electrostatic force on particle B due to the other two charges

Directions Q. Nos 1 and 2: The coordinates of 1kg 2kg 3kg and 4kg masses are (0 0) (1 0) (0 1) and (1 1) respectively.

A boat is travelling 4.00 m/s north across a river that is 125 m wide. The river current is moving 2.10 m/s east. What is the actual speed of the boat?

Air is contained in a piston cylinder arrangement as shown in Fig. The piston can be assumed to be massless, frictionless, and perfectly insulated. 10 kg of dry ice (solid CO2) is placed on top of the piston. The initial conditions for air inside the cylinder are P1=121 kPa, T1= 300 K. Dry ice sublimates gradually, and its mass reduces to 5 kg. Ambient air is always at room temperature (27oC) and atmospheric pressure. (Given: R=287 J/kg ·K, g = 9.8 m/s2 , CP/CV for air = 1.4; Neglect all heat transfer to the dry ice block.)

a) Assuming the cylinder to be perfectly insulated, calculate the specific work done for the process.

b) Assuming the cylinder to be perfectly conducting, what is the heat required per unit mass of air to complete the process?

c) Plot the processes described in (a) and (b) together on a Pv diagram. From this plot, which process appears to have more work? Explain.

A small sample of coal, when completely converted into energy, releases 3.75 * 10 ^ 34j What is the initial mass of coal, assuming the final mass is 0? 

It was stated in the text that the Debye temperature thetaD is proportional to (Y/M)^1/2, where Y is Youngs modulus and M the atomic mass. For solids of similar chemical and structural characteristics, the parameters Y are nearly equal, and thus thetaD ~ 1/M^1/2. Plot thetaD versus M^-1/2 for the alkali metals (Li, Na, K, Rb, Cs), the noble metals (Cu, Ag, Au), the covalent crystals (C, Si, Ge, Sn), and discuss how well this prediction is satisfied.

Use the table of specific heat capacities to solve this problem. A bar of aluminum is heated to 90.0C and then placed into 10.0 L of water at 20.0 degrees * C . If the mixture cools to 22.4 degrees * C , what is the mass of the aluminum bar? 

a 55kg student climbs 5.6m up a rope gym class at a constant speed of 1.6 m/s . Determine the power exerted by the student with and without determining the time taken.