Two equal forces are applied to a door. The first force is applied at the midpoint of the door; the second force is applied at the doorknob. Both forces are applied perpendicular to the door. Which force exerts the greater torque?A) the first at the midpointB) the second at the doorknobC) both exert equal non-zero torquesD) both exert zero torquesE) Additional information is needed.

The torque is more for the force applied at the doorknob.

The torque is defined as the force that allows for a rotation. A torque is measured by means of product between the force applied with the distance between the point of force application to the axis of the rotation of the body.

So in the first case, the torque is equal to the product of the force applied and the distance between the midpoint to the hinge of the door. In the second case, the torque is equal to force applied with the distance of doorknob from the hinge.

As the forces are equal, and the distance of the doorknob from the hinge is greater than that of midpoint, then the torque in the second case is more than that of 1st case.

the chart show the masses and velocities of two colliding objects that stick together after a collision.

according to the law of conservation of momentum, the momentum of the object after the collision is  

answer

1,500

kg • m/s.