A 1.7 kg otter starts from rest at the top of a muddy incline 98.6 cm long and slides down to the bottom in 0.5 s. What net external force acts on the otter along the incline?
An otter that is at rest slides down a muddy incline 98.6 cm long. The time taken is 0.5 seconds. The mass of the otter is 1.7 kg.
The acceleration of a body with a mass m on which the force F acts is given by a = F/m m/s^2. The distance moved by a body with an initial velocity u that is accelerating at an acceleration a in t seconds is given by D = u*t + (1/2)*a*t^2.
Here, the otter travels a distance 98.6 cm in 0.5 seconds. The initial velocity is 0. Substituting the given values we get:
0.986 = (1/2)*a*(0.5)^2
=> a = 7.888 m/s^2
To accelerate the otter by this magnitude the force required is 7.888*1.7 = 13.4096 N.
The net force acting on the otter that results in the given motion is 13.4096 N.