One particular descent goes from 2100m to 1600m. Assuming the work done against friction is 90% of the potential energy change of the cyclist and the cycle, what increase in speed in km/h can a rider attain by the end of the descend

Keneila is attempting to ski down a 20 m high friction free hill for the first time. she has a speed 10 m/s at the top. what is her kinetic energy when she is a the bottom, 20 m ? (a)2500 j (b)9800 j (c)12300 j (d)3100j (e)15000j

Aforce of 240.0 n causes an object to accelerate at 3.2 m/s2. what is the mass of the object?

Aturntable a is built into a stage for use in a theatrical production. it is observed during a rehearsal that a trunk b starts to slide on the turntable 10 s after the turntable begins to rotate. knowing that the trunk undergoes a constant tangential acceleration of 0.31 m/s2, determine the coefficient of static friction between the trunk and the turntable.