An object of irregular shape has a characteristic length of 1 m and is maintained at a uniform surface temperature of 375 k. when placed in atmospheric air at a temperature of [infinity] 300 k and moving with a velocity of 100 m/s, the average heat flux from the surface to the air is 20,000 w/m2. if a second object of the same shape, but with a characteristic length of 5 m, is maintained at a surface temperature of 375 k and is placed in atmospheric air at [infinity] 300 k, what will the value of the average convection coefficient be if the air velocity is 20 m/s?

If an inclined plane is 5 m long and 2 m high, what is its mechanical advantage? a. 2.5 b. 3 c. 7 d. 10

Acar moves at 12m/s and coasts up a hill with a uniform acceleration of -1.6m/s2. how far has it traveled after 6.0s?

The ultracentrifuge is an important tool for separating and analyzing proteins. because of the enormous centripetal accelerations, the centrifuge must be carefully balanced, with each sample matched by a sample of identical mass on the opposite side. any difference in the masses of opposing samples creates a net force on the shaft of the rotor, potentially leading to a catastrophic failure of the apparatus. suppose a scientist makes a slight error in sample preparation and one sample has a mass 10 mg larger than the opposing sample. if the samples are 12 cm from the axis of the rotor and the ultracentrifuge spins at 70,000 rpm, what is the magnitude of the net force on the rotor due to the unbalanced samples? ( be thorough on your answer)