When a block with mass 30.0 kg is placed on a ramp that is inclined at an angle α below the horizontal, it slides down the ramp with an acceleration of 4.2 m/s^2. The ramp is not frictionless. To increase the acceleration of the crate, a downward vertical force F is applied to the top of the crate. What must F be to increase the block's acceleration to 9.8 m/s^2?

explanation:

an enlarged virtual image is the answer

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.

at right angles to each other