PHYSICS ASSIGNMENT A. If a cyclist of mass 70kg uses a bicycle of mass 7kg, how much work must the cyclist do against gravity in order to ascend to 2100m from sea level.

b. 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 cycle, what Increase in speed in km/h can a rider attain by the end of the descent?

c. What is the average rate of energy conservation of the cyclist and cycle if the descent in part 'b' takes 1 minute at constant speed.

(Acceleration due to gravity, g = 10ms^-2)

Afaulty model rocket moves in the xy-plane (the positive y direction is vertically upward). the rocket's acceleration has components ax(t) = ? t2 and ay(t) = ? ? ? t, where ? = 2.50 m/s4 , ? = 9.00 m/s2 , and ? = 1.40 m/s3 . at t = 0 the rocket is at the origin and has velocity ~v0 = v0x ? i + v0y ? j with v0x = 1.00 m/s and v0y = 7.00 m/s. (a) calculate the velocity and position vectors as functions of time. (b) what is the maximum height reached by the rocket? (c) sketch the path of the rocket. (d) what is the horizontal displacement of the rocket when it returns to y = 0?