Answer:
0.495m
Explanation:
The kinetic energy of the stone will be equal to the work done by the spring
Mathematically;
W = KE
1/2ke² = 1/2mv²
ke² = mv²
k is the spring constant = 150N/m
e is the extension
m is the mass = 0.015kg
v is the velocity = 70m/s
Substitute
150e² = 1/2 * 0.015 * 70²
150e² = 36.75
e² = 36.75/150
e² = 0.245
e = √0.245
e = 0.495m
Hence the extension of the catapult is 0.495m
