What is the gravitational force between two identical 50,000 kg asteroids whose centers of mass are separated by 1000 m?

A 0.450 kg ice puck, moving east with a speed of ${\displaystyle 3.00\frac{m}{s}}$ has a head in collision with a 0.900 kg puck, initially at rest. Assuming a perfectly elastic collision what will be the speed and direction of each object after the collision?

A block is on a frictionless table, on earth. The block accelerates at ${\displaystyle 5.3\frac{m}{s^2}}$ when a 10 N horizontal force is applied to it. The block and table are set up on the moon. The acceleration due to gravity at the surface of the moon is ${\displaystyle 1.62\frac{m}{s^2}}$. A horizontal force of 5N is applied to the block when it is on the moon. The acceleration imparted to the block is closest to: 
a) ${\displaystyle 2.9\frac{m}{s^2}}$ 
b) ${\displaystyle 3.2\frac{m}{s^2}}$ 
c) ${\displaystyle 3.4\frac{m}{s^2}}$ 
d) ${\displaystyle 2.7\frac{m}{s^2}}$ 
e) ${\displaystyle 2.4\frac{m}{s^2}}$

A uniform plank of length 2.00 m and mass 30.0 kg is supported by three ropes. Find the tension in each rope when a 700-N person is 0.500 m from the left end.

A space traveler weights 540 N on earth. what will the traveler weigh on another planet whose radius is three times that of earth and whose mass is twice that of earth ?