3. A swimmer is oriented perpendicular to the parallel banks of a river. If the swimmer's velocity is 2 m/s and the current is 0.5 m/s, what will be the swimmer's resultant velocity? (Hint: Use Pythagoras's theorem.) 4. The relative angle at the knee changes from 180 degrees to 95 degrees during the knee flexion phase of a squat exercise. If 10 complete squats are performed, what is the total angular distance and the total angular displacement undergone at the knee? 5. How much force must be applied by a kicker to give a stationary 2.5 kg ball an acceleration of 40 m/s? ? (Hint: Use one of Newton's laws.)