A4 kg object attached to a horizontal string moves with constant speed in a circle on a frictionless horizontal surface. the kinetic energy of the object is 72 j and the tension in the string is 426 n. find the radius of the circle. answer in units of m

r = 0.338 m

Explanation:

Mass = m = 4 kg

T = 426 N

K.E= 1/2 m V²

⇒V² = 2 * K.E/m

⇒ V² = 2 * 72 / 4

⇒ V² = 36

⇒ V = 6 m/s

Now

Fc = mV²/ r

⇒ r = mV²/Fc

Fc = T  ( According to Newton's 3rd law)

⇒ r = mV²/ T

⇒ r = 4 * 6²/ 426 m

⇒ r = 0.338 m

the independent variable, the one that is intentionally manipulated, is whether or not the car hits the barrier.

the dependent variable, the one that you measure the response in, is the distance that the washers travel.

we're given that v₀ = 0 and a = 5.4 m/s². therefore, since v = at + v₀ for constant acceleration the equation for velocity is

after 28s,

m/s

which i would round to 150 m/s as my final answer