In the diagram shown below, a = 250mm and b = 60 mm. Each of the two elastic rub
ID: 2997645 • Letter: I
Question
In the diagram shown below, a = 250mm and b = 60 mm. Each of the two elastic rubber bands of the slingshot has an unstretched length of 130 mm and a stiffness of k = 5 kN/m. The mass of the pellet is 20 g. The rubber bands are pulled back to the position shown and released from rest. A) Determine the Maximum potential energy stored in the two rubber bands. and B) What is the maximum height that the pellet can reach?
In the diagram shown below, a = 250mm and b = 60 mm. Each of the two elastic rubber bands of the slingshot has an unstretched length of 130 mm and a stiffness of k = 5 kN/m. The mass of the pellet is 20 g. The rubber bands are pulled back to the position shown and released from rest. A) Determine the Maximum potential energy stored in the two rubber bands. and B) What is the maximum height that the pellet can reach?Explanation / Answer
lenght of each rubber band = sqrt(a2+b2)= 257 mm
extra lenght streched x = 257-130 = 127mm
Max potential energy in rubber bands = 2*(0.5kx2)
= 5000*0.1272 = 80.65 J
By conservation of energy
rubber bands potential energy is converted to pellet's potential energy
mgh = 80.65
0.02*9.8*h = 80.65
h = 411.48 m
height above the level =411.48 - 0.25 = 411.23 m