Aforce platform is a tool used to analyze the performance of athletes measuring the vertical force that the athlete exerts on the ground as a function of time. starting from rest, a 67.0-kg athlete jumps down onto the platform from a height of 0.720 m. while she is in contact with the platform during the time interval 0 < t < 0.800 s, the force she exerts on it is described by the function
f = 9 200t − 11 500t2
where f is in newtons and t is in seconds.
(a) what impulse did the athlete receive from the platform?
n · s up

(b) with what speed did she reach the platform?
m/s

(c) with what speed did she leave it?

(d) to what height did she jump upon leaving the platform?

In a steady-flow steam power plant system, two adiabatic high-pressure and low-pressure turbines ane used to generate power. superheated steam enters the high-pressure turbine at 8 mpa and 550°c. the steam expands in the high-pressure turbine to a saturated vapor at 3 mpa. in order to increase the powe generation of the power plant, another steam turbine working in a lower pressure ranges is deployed. the outlet vapor from the first turbine is heated up at a boiler to the temperature of 500 c at the constant pressure of first turbine's outlet (3 mpa). then, the vapor enters the second turbine and produces extra work. the exit conditions of the second turbine are 5o kpa and 90 percent quality. if the total power output of the power plant is 25 mw, determine a) the mass flow rate of the water (kg/s). b) heat transfer rate in the boiler (mw). (30 points) 3 mpa 00 c 8 mpa s0 c high pres turbine low pres boiler turbine 50 kpa 3 mpa 09 saturated vapor t heat engine, shown in the figure, operates between high temperature and low temperature of through a heat 4. a carnot tn and tu respectively. this heat engine receives energy from a heat reservoir at t exchanger where the heat transferred is proportional to the temperature difference as ? = k (z,-7, ). it rejects heat at a given low temperature tl. to design the heat engine for maximum work output, find the high temperature, th, as a function of tes and t. (15 points) qe

Clothes dryer uses about 7 amps of current from a 240 volt line. how much power does it use?

The speed of light can be used to measure the