Recent content by GoodOldLimbo

Homework Statement If a steel ball of mass 100 grams at a temperature of 100° is dropped into 1 litre of water at 20°C, what is the temperature rise? What would happen if it were dropped into a mixture of ice and water at 0°C? Homework Equations I assume that I'm required to use ΔQ =...

Homework Statement A tank contains 125 litres of water. If it's temperature is 20C, how long would it take for a 2kW immersion heater to raise its temperature to 60C if the average rate of heat loss is 150W? Homework Equations I am using the specific heat capacity equation: ΔQ =...

Homework Statement A camera lens has focal length 55mm and an object is 500mm away. Calculate the position of the image and the magnification (or reduction) Homework Equations 1/u + 1/v = 1/f u = Object Distance v = Image Distance f = focal length m = magnification The...

I'm still stuck on this question. Is anyone willing to help me? I'm still not sure how to go from sin^2 θ / cos θ = 106.7 to sin^2θ + cos^2 θ = 1.

Well, when I get to sin2θ + cos2 θ = 1, I assume you can cancel out the square because the square root of one is one. But if it's sinθ + cosθ = 1, I'm not really sure how to go about that. cos-1 x 1 = 0, and sin-1 x 1 = 90, so θ = 90? Even then, I'm not really sure how to write that.

Homework Statement A conical pendulum has length (L) 1.5m and rotates at 4ms-1. What is it's angle (θ) to the vertical? Homework Equations r = Lsinθ tanθ = v2/Lsinθg tanθsinθ = v2/Lg sinθsinθ/cosθ = v2/Lg sin2θ/cosθ = v2/Lg sin2θ + cos2θ = 1 The Attempt at a...

Homework Statement A Centrifuge rotates at 12000rpm. What is this in radians per second? If the radius of this centrifuge is 150mm, what is the centripetal acceleration? Homework Equations v2 / r v = rω a = rω2 The Attempt at a Solution First I converted the 12000rpm...