text: work, energy, power, and momentum? a 2.4 kg block slides over a horizontal, frictionless surface until it encounters a spring with a force constant of910 n/m. the block comes to a speed of .056 m/s while compressing the spring 4.25 cm. what is the initial speed of the block? force on spring (910 (n / m)) * .045 m = 40.95 newtons  f = ma 40.95 newtons = 2.4 kg * a a = (40.95 newtons) / (2.4 kilograms) = 17.0625 m / s2