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  1. Q

    Derivation of area of trajectory of projectile

    Homework Statement This is a problem about an aircraft flying above a cannon which is capable of firing in any direction. The plane's height, velocity and the speed of the projectile fired by the cannon are given (I am not trying to get help in solving the problem, so the numbers are not...
  2. Q

    Two soap bubbles coalesce, what is the surface tension?

    Homework Statement Two soap bubbles of equal radius 'r' coalesce isothermally to form a bigger bubble of radius 'R'. If the atmospheric pressure is P0, find the surface tension of the soap solution. Homework Equations Surface energy = surface tension x increase in area (W = T.ΔA)...
  3. Q

    Force exerted by water on a tube

    Homework Statement A tube of uniform cross-section is bent to form a circular arc of radius R, forming three quarters of a circle. A liquid of density ρ is forced through the tube with a linear speed 'v'. Find the net force exerted by the liquid on the tube. Homework Equations F =...
  4. Q

    Binomial theorem proof

    Homework Statement Show that if the greatest term in the expansion of (1+x)2n is also the greatest coefficient, then x lies between n/n+1 and n+1/n. Homework Equations No idea. The Attempt at a Solution Don't know where to start.
  5. Q

    Angular velocity of a ball

    Homework Statement A ball of mass 0.5 kg is attached to the end of a string of length 0.5 m. The ball rotates in a horizontal circular path about a vertical axis. The maximum tension on the string cannot exceed 324 N. What is the maximum possible angular velocity of the ball in rad/s ...
  6. Q

    Confusion regarding resolution of forces

    Homework Statement A force which is at an angle θ to the horizontal (not being 90°) has two components Fx = FCosθ and Fy = Fsinθ along the x and y direction. However, when working out problems regarding objects on an incline, the horizontal (parallel to the slope) component of Normal force...
  7. Q

    Multiple Pulleys problem

    Homework Statement The block B moves to the right with a constant velocity of 30 cm/s. Given this, which of the following is correct: 1. Speed of block A is 15 cm/s 2. Speed of point P is 60 cm/s 3. Speed of point P is 30 cm/s 4. Speed of block A is 40 cm/s Homework...
  8. Q

    Finding the horizontal range of a projectile when maximum height is not known

    Homework Statement A projectile is launched with an velocity of 40 m/s and crosses a tower of height 20.4 m after 2 seconds. Find the angle of projection with the horizontal and the horizontal range. Homework Equations S = ut - 1/2 gt2 where S is the distance, u = 40 Sin\Theta and g...
  9. Q

    Heights of two balls thrown at the same time

    Homework Statement A ball is thrown at angle \Theta and another ball is thrown at an angle (90-\Theta) with the horizontal from the same point with velocity 39.2 m/s. The second ball reaches 50 m higher than the first. Find the heights. Homework Equations v = u -gt where v is the...
  10. Q

    Given the ionization energy, find the number of protons

    Homework Statement A hydrogen like system has ionization energy of 11808 kJ/mol. Find the number of protons in the nucleus. Homework Equations Not sure. Should I use the formula En = E1/n2? The Attempt at a Solution The ionization energy of H is 1312 kJ/mol. The ionization...
  11. Q

    Amount of CaO required to removed HCO3- from 1 kg of hard water

    Homework Statement A sample of hard water contains 305 ppm of HCO3- ions. What is the minimum mass of CaO required to remove HCO3- completely from 1 kg of water sample? Homework Equations Ca 2+ + 2HCO3 + CaO = 2CaCO3 + H2O The Attempt at a Solution Since the HCO3- ions are...
  12. Q

    Finding atomic weight from vapor density of metal chloride

    Homework Statement Vapor density of a metal chloride is 66. Its oxide contains 53% metal. The atomic weight of the metal is ? Homework Equations vapor density = 0.5 * molar mass The Attempt at a Solution Using the above formula, I found the molar mass of the metal chloride as...
  13. Q

    Find the amount of Barium Sulphate precipitated

    Homework Statement 8 grams of Sulfur is burnt in Oxygen to form SO2 which is oxidized by Chlorine water. The solution is treated with BaCl2 solution. The amount of BaSO4 precipitated is ? Homework Equations SO2 + Cl2 + H2O = SO3 + 2HCl SO3 + HCl + BaCl2 = BaSO4 + HCl I do not know if the...
  14. Q

    Stoichiometry - 0.7g of Na2CO3.xH2O were dissolved in water

    Homework Statement 0.7g of Na2CO3.xH2O were dissolved in water and the volume was made to 100 ml, 20 ml of this solution required 19.8 ml of N/10 HCl for complete neutralization. The value of x ? Homework Equations Na2CO3 + 2HCl = 2NaCl + H2O + CO2 The Attempt at a Solution I...
  15. Q

    Stoichiometry problems thread

    Stoichiometry problem Homework Statement 1 g of H2O2 solution containing x % of H2O2 by weight required x ml of KMnO4 for complete oxidation in acid medium. What is the normality of KMnO4 solution? Homework Equations H2O2 + KMnO4 => 2KOH + 2MnO2 + 2O2 The Attempt at a Solution...
  16. Q

    Stoichiometry problem

    Homework Statement How many grams of potassium di chromate (K2Cr2O7) are present in 1 lit of its N/10 solution in acid medium? Homework Equations gram eq = NV = g/E = xg/M The Attempt at a Solution gram eq = NV = 0.1 * 1 = 0.1 g = gram eq * mol wt / valence factor (The valence factor I...
  17. Q

    Vector resolution

    Homework Statement The airspeed of a small plane is 200 km/h. The wind speed is 50.0 km/h [E]. Determine the velocity of the plane relative to the ground if the pilot keeps the plane pointing in each of the following directions. a) East (250 km/h [E] ) b) West (150 km/h [W] ) c) North (206...
  18. Q

    What is the derivation for decrease in g with depth?

    Homework Statement We know that 'g' decreases with height and the derivation for the formula is straight enough, but how is the formula for decrease of 'g' with depth derived? The Attempt at a Solution If an object is taken to a height 'h' above the surface of the earth and...
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