Final answer:
Force needed is 14.2 N; work done is 985.2 J; mass of the object is 2.7 g; the specific heat of the object is 0.64 J/g°C.
Step-by-step explanation:
1) The force needed for a machine to output 345 J of work over a distance of 24.3 m can be calculated using the work equation Work = Force × Distance. Therefore, the force is Work ÷ Distance which equals 14.2 N (rounded to one decimal place).
2) The work (W) involved in changing an object's velocity can be determined using the work-energy principle, which is W = ½ m (v²_final - v²_initial). For an object of mass 0.98 kg with an initial velocity of 23.4 m/s and final velocity of 43.5 m/s, the work is 985.2 J (rounded to one decimal).
3) The mass of an object with a gravitational potential energy (GPE) of 23.4 J dropped from 903 m can be found using the equation GPE = mgh, thus mass equals GPE ÷ (gh), where g is the acceleration due to gravity (9.8 m/s²). The mass is approximately 0.0027 kg or 2.7 g.
4) To find the specific heat (c) of an unknown object with mass 23 g, a temperature change of 230 degrees Celsius, and heat output of 3400 J, use the formula Q = mcΔT. Therefore, the specific heat is 3400 J ÷ (23 g × 230°C), resulting in approximately 0.64 J/g°C.