Initial speed of a rock on Planet Glob

The small planet "Glob" has a mass of 6.40à—1018 kg and a radius of 6.10à—104 m. An astronaut on the surface of Glob throws a rock straight up. The rock reaches a maximum height of 1.30 km above the surface of the planet before it falls back down. What was the initial speed of the rock as it left the astronaut's hand? (ignore air resistance)

Calculating the contact force on two blocks.

Two blocks are in contact on a frictionless table. A horizontal force F is applied to M2, as shown. If M1 = 1.81 kg, M2 = 3.26 kg, and F = 5.50 N, find the size of the contact force between the two blocks. (Block M1 is touching block M2, sitting on a table.)

turntables

Shown from the top view are six blocks that are sitting at rest on rotating turntables. All of the turntables have the same rotation rate (i.e. same frequency). The masses of the blocks and how far out from the center they sit varies. The specific values are given in the figures. Which of the following statements are true about the situations depicted in the figures above? (Give ALL correct answers: B, AC, BCD.., or None ) A) The blocks in pictures A and B experience the same centripetal force B) The linear (tangential) speed of the blocks in pictures A, B and F is the same C) The period of rotation of the blocks is the same in pictures A, B and E D) The net force on the blocks i... click for more

scales

The figures depict situations where a person is standing on a scale in eight identical elevators. Each person weighs 600 N when the elevators are stationary. Each elevator now moves (accelerates) according to the specified arrow that is drawn next to it. In all cases where the elevator is moving, it is moving upward. Which of the following statements are true about the situations depicted in the figures above? (Give ALL correct answers: B, AC, BCD.., or None ) A) The normal force provided by the scale is greatest in pictures A and E B) The net force on the person is zero in all pictures C) The scales read zero weight in pictures D, E and G D) The weight the scales read is the sam... click for more

blocks and ropes

The eight figures show various situations where blocks of different weights are attached by ropes to rigidly fixed objects or to other blocks, which are attached to fixed objects. The situations differ in a number of ways, as the figures show, but all situations represent static equilibrium (i.e. nothing is moving). The weights of the blocks are given in the figures, as well as the magnitudes and directions of any other forces that may be acting. Our interest is solely in the rope that is designated R in each figure. Which of the following statements are true about the situations depicted in the figures above? (Give ALL correct answers: B, AC, BCD.., or None ) A) The tension in the ro... click for more