Afreight train travels from miamistown to fredricksburg, a distance of 680 km. if the route takes 12.2 hours, what is the train’s average speed in kilometers per hour (km/h)?

Abucket full of water weights 4 kg and water well is 10m deep. a girl draws water from the well. it takes the girl 3 minutes to draw a bucket full of water from the well. what is the power of the girl?

What is the temperature in degrees celsius of a substance with a tempature of 49k

Two resistors r1 and r2 may be connected either in series or parallel across an ideal battery with emf ε. we desire the rate of energy dissipation of the parallel combination to be 8.75 times that of the series combination. if r1 = 105 ω, what are the (a) smaller and (b) larger of the two values of r2 that result in that dissipation rate?