A box is moved 10 m across a smooth floor by a force F making a downward angle with the floor, so that there is effectively a 4 N force acting parallel to the floor in the direction of motion and a 3 N force acting perpendicular to the floor. The force F acts for 20 seconds. The impulse delivered to the box by the floor during this process has magnitude

Zero

Explanation:

Impulse is defined as the change in momentum.

Impulse is also defined as the product of force and the time duration of application of the force.

In the given problem, since there is no motion in the vertical direction, therefore the velocity of the box along the vertical direction is zero. So, momentum of the box along the vertical is also zero.

Hence the change is momentum is also zero along vertical direction.

Thus the impulse delivered by the box is zero.

at positions a, g kinetic energy is maximum.

at position d, potential energy is maximum.

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.