Answer: a disadvantage of using a ramp is that it is not safe
Answer:
I do belive that it is B hrs cn I an gn
Force = mass * acceleration
F = 15 *8 = 120 Newton
Base SI unit is the unit that used for simple quantity like time=second and length= meter. They only have one unit.
Derived unit is more complex because you multiply or divide at least two base SI, making it have more than 1 unit. The example could be velocity which was time/length = m/s