While exercising in a fitness center, a man lies face down on a bench and lifts a weight with one lower leg by contracting the muscles in the back of the upper leg. The weight has mass 12.5 kg, and is a distance of 28.0 cm from the knee joint. The moment of inertia of the lower leg is 0.900 kg ⋅ m 2 , the muscle force is 1450 N , and its effective perpendicular lever arm is 3.45 cm. Find the magnitude of the angular acceleration α of the weight. α = rad / s 2 How much work W is done if the leg rotates through an angle of 20.0 ° with a constant force exerted by the muscle? W =

Use the library or internet to research each planet. make a chart comparing the following: approximate surface temperature relative surface gravity compared to earth atmospheric gases water in any form: solid, gas, or liquid when you have completed your chart, use the information you have collected to answer the following questions: which is the hottest planet? which is the coldest planet? which planet's temperature is closest to that of earth? (note: water boils at 100°c/212°f. water freezes at 0°c/32°f) which planet has the greatest gravitational attraction? which planet has the least gravitational attraction? which planet's gravitational pull is closest to that of earth? do any of the planets have oxygen in their atmosphere? which planet's atmosphere most resembles that of earth? do any of the planets have flowing water? which planet's water resources (solid, gas, or liquid) might be close to the amount on earth? which planet most resembles earth in terms of all of the factors: temperature, gravity, atmosphere, and water? if earth became an uninhabitable planet, which planet do you think would be the next best to live on? explain your answer.