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...
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...