A 70 kg firefighter slides, from rest, 4.3 m down a vertical pole. (a) If the firefighter holds onto the pole lightly, so that the frictional force of the pole on her is negligible, what is her speed just before reaching the ground floor? (b) If the firefighter grasps the pole more firmly as she slides, so that the average frictional force of the pole on her is 500 N upward, what is her speed just before reaching the ground floor?

Question 1: A 60 kg skier starts from rest at height H = 20 m above the end of a ski-jump ramp and leaves the ramp at angle 0=28o. Neglect the effects of air resistance and assume the ramp is frictionless. (a) What is the maximum heighth of his jump above the end of the ramp? (b) If he increased his weight by putting on a backpack, would h then be greater, less, or the same? End of - ramp

(a) Salim who participates in motor race, leaves the end of a ramp with a speed of 90km/hr as in Figure. If his speed is 85.0 km/r when he reaches the 90 km/h peak of the path, what is the maximum height that he | reaches? Ignore friction and air resistance. (b) A body of mass 6 kg is acted upon by a force of 5 N is moving along a rough floor at a constant speed of 3.5 m/s. Calculate the power consumed in 15 s, and the force of friction acting on the object (a) To find the depth of a water well at home, Martha and Amira drop a heavy rock into the well. After 3s, the rock is 4. dropped, they hear a splash caused by the impact of the rock on the water. What is the height of the well? (Speed of sound in air is 340 m/s). (b) Professor Walter Lewin, for his famous Physics experimental demonstration, hanged a bowling ball from the ceiling by a rope. He then pulls the ball away from its equilibrium position and holds it adjacent to his nose, as shown. He releases the ball so that it swings…