posted by Leah .
Hans uses a wheelchair. Although he has a rampto in his house, he finds it difficult to get his wheelchair up the ramp. Whcih modification would make it easier for Hans to get in his house?
a. increase the length of the ramp
b. increase the friction between the wheels and the ramp surface
c. sdecrease the length of the ramp
d. decrease the friction between the wheels and the ramp surface