A small rock with mass 0.12 kg is fastened to a massless string with length 0.80 m to form a pendulum. The pendulum is swinging so as to make a maximum angle of 45 with the vertical. Air Resistance is negligible.
a) What is the speed of the rock when the string passesthrough the vertical position?
b) What is the tension in the string when it makes an angle of 45 with the vertical?
c) What is the tension in the string as it passes through the vertical?
A 730-N man stands in the middle of a frozen pond of radius 5.0 m. He is unable to get to the other side because of a lack of friction between his shoes and the ice. To overcome this difficulty, he throws his 1.2 kg physics textbook horizontally toward the north shore , at a speed of 5.0 m/s. How long does ittake him to reach the south shore?
A 1.0 kg ball and a 2.0 kg ball are connected by a 1.0-m-long rigid, massless rod. The rod is rotating cw about its center of mass at 20 rpm. What torque will bring the balls to a halt in 5.0 s? Answer in Nm.
An adventurous archaeologist crosses between two rock cliffs by slowly going hand-over-hand along a rope stretched between the cliffs. He stops to rest at the middle of the rope (Fig. 1) The rope will break if the tension in it exceeds N and our hero's mass is 86.5 kg.
Figure 1 a) If the angle is , find the tension iin the rope.
b) What is the smallest value the angle can have if the rope is not to break?