In the winter sport of curling, players give a 20 kgstone a push across a sheet
ID: 1997528 • Letter: I
Question
In the winter sport of curling, players give a 20 kgstone a push across a sheet of ice. The stone moves approximately 40 m before coming to rest. The final position of the stone,in principle, only depends on the initial speed at which it is launched and the force of friction between the ice and the stone, but team members can use brooms to sweep the ice in front of the stone to adjust its speed and trajectory a bit; they must do this without touching the stone. Judicious sweeping can lengthen the travel of the stone by 3 m.
A.) The sweepers in a curling competition adjust the trajectory of the stone by?
b. Increasing the coefficient of friction between the stone and the ice.
c. Changing friction from kinetic to static.
d. Changing friction from static to kinetic.
B.) Suppose that the stone is launched with a speed of 3 m/s and travels 40 m before coming to rest. What is the approximatemagnitude of the friction force on the stone?
a. 0 N
b. 2 N
c. 20 N
d. 200 N
C.) Suppose the stone's mass is increased to 40 , but it is launched at the same 3 . Which one of the following is true?
a. Decreasing the coefficient of friction between the stone and the ice.b. Increasing the coefficient of friction between the stone and the ice.
c. Changing friction from kinetic to static.
d. Changing friction from static to kinetic.
B.) Suppose that the stone is launched with a speed of 3 m/s and travels 40 m before coming to rest. What is the approximatemagnitude of the friction force on the stone?
a. 0 N
b. 2 N
c. 20 N
d. 200 N
C.) Suppose the stone's mass is increased to 40 , but it is launched at the same 3 . Which one of the following is true?
a. The stone would now travel a longer distance before coming to rest. b. The stone would now travel a shorter distance before coming to rest. c. The coefficient of friction would now be greater. d. The force of friction would now be greater.Explanation / Answer
A) A. Decreasing the coefficient of friction between the stone and the ice
B) b. 2 N
d = 40 m, m = 20 kg
Work done = F * d
F = [1/2 m v2] / d
= (1/2 * 20 * 32) / (40) = 2.0 N
C) b. The stone would now travel a shorter distance before coming to rest