This is from the radicals unit but it's a physics question so I'm confused

10. The kinetic energy E, in joules J , of a moving object can be expressed as E, = - mv , where 2 m is the mass in kilograms kg , and v is the speed at which the object is moving in metres per second m/ s . If the kinetic energy of a 2.5 kg object is 1150 J, determine the speed of the object to the nearest tenth of a m/s . (2 marks)