Spacecraft a and b are in the same circular earth orbit with a period of 2 hours. spacecraft b is 6 km ahead of spacecraft a. at t = 0, spacecraft b applies an in-track delta-v (retrofire) of 3 m/s. using a clohessy-wiltshire frame attached to spacecraft a, determine the distance between a and b at 30 minutes and the velocity of b relative to a-

The 5-kg cylinder is initially at rest when it is placed in contact with the wall b and the rotor at a. if the rotor always maintains a constant clockwise angular velocity v = 6 rad> s, determine the initial angular acceleration of the cylinder. the coefficient of kinetic friction at the contacting surfaces b and c is mk = 0.2.

The force acting on a beam was measured under the same operating conditions and a sample of 5 data points was collected. this process was repeated by 3 observers. the pooled standard deviations of these 3 data sets was 1.21. determine the true mean force using all pooled data (with a 95% probability). the result should look like this: true mean = mean +/- margin of error

Avolcano erupts next to a grassland area in a valley. a. describe three ways in which material released by the volcano could impact the grassland area. b. describe three ways in which the grassland ecosystem could recover after a volcanic eruption.