Question

Say you want to make a sling by swinging a mass M of 1.5 kg in a horizontal circle of radius 0.058 m, using a string of length 0.058 m. You wish the mass to have a kinetic energy of 14.0 Joules when released. How strong will the string need to be

Answer 1

Answer:

482.75N

Explanation:

Centripetal force and energy

Given data

mass m= 1.5kg

radius r =0.058m

Kinetic energy KE= 14J

we know that the expression for centripetal force is

F= mv^2/r

also kinetic energy is given as

KE= 1/2 mv^2  

Multiply this by 2 and divide by r  

KE = 2 * 1/2 m v^2 / r  

KE= mv^2 /r

KE= F -----------------1

this means that

F = 2KE/r

Substituting our given data we have

F= 2 * 14.0 / 0.058

F=28/0.058

F=482.75N