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During the time when a man had flu, he ran a fever of 2.0oC above normal. His body temperature was 39.0oC instead of the normal 37.0oC. Assuming that the man has a mass of 80 kg and that the human body is mostly water, how much heat is required to raise his temperature? [Take specific heat capacity of liquid as, C = 4186 J / kg.oC]
How much energy is lost by 20 kg copper if it is cooled from 50°C to 30°C?
A 2.0 mol. sample of an ideal gas is kept at 1.0◦c during an expansion from 2.0 L to 9.0 how much energy transfer by heat occurs with the surroundings in this process?
What is the resultant temperature when 100g of steam at 100°C is passed through 500 g of ice at −20°C. The specific heat
of ice is 0.5 cal / g°C.
A homogeneous rod of mass m=1kg and length L=2m is hinged in A to vertical wall and forms an angle α = 45’ with it. A mass of M = 12kg is attached at a distance D = 3/4L and a rope with negligible mass is attached at its extremely which supports the maximum tension | Tmax|= 1000N.
Calculate:
a) The rope tension ( magnitude and direction)
b) The maximum mass Mmax and the range of values that M can assume without the rope breaking.
A block of mass M = 2kg is placed inside a rigid tube with length L= 2m connected to two springs of resisting lengths L1= 80cm and L2 =100cm, with spring constant k1= 200 N/M and k2= 300 N/M respectively connected at the ends A and B of the tube. Determine the elongations of the two springs when the tube AB is positioned Vertically.
Finally consider one configuration in which the tube rotates in a horizontal plane centered at B, and determine for which value of the rotation period the spring k1 is no longer elongated.
two forces are applied to a 0.45kg toy car, f1 = (2.5n, 1.5n) and a second force f2 = (-2.25n, -0.75n). if the car starts from rest, calculate the modulus of its velocity after 5 seconds.
A mass m at the end of a spring vibrates with a frequency of 0.90 Hz. When an additional 520-g mass is added to m, the frequency is 0.50 Hz.
a) What is the value of m?
b) Calculate the total mass needed for the system to vibrate with a freq. of 0.45 Hz.
A car of mass 1000 kg had its springs compressed vertically by 2.6 cm when a driver of mass 62 kg climbed into it. If damping is ignored what is the frequency of vibration when the car hits a bump while driving?
A heat engine produces 30, 000 J of mechanical work per second of operation. If its efficiency is 20% how much heat is discharged from this engine per second?
