A net force of 10 N accelerates a 2 kg mass over a distance of 20 m.
(a) What is the work done by this net force?
J
(b) What is the increase in kinetic energy of the mass?
J
2007-02-08 03:27:10 · 2 answers · asked by bibun 2 in Science & Mathematics ➔ Physics
a) A work done is W = Fx = 10 N x 20 m = 200 J
b) The increase in KE is equal to the work done, so ΔEK = W = 200 J
2007-02-08 03:31:53 · answer #1 · answered by Dorian36 4 · 0⤊ 0⤋
A. Work = Force x Distance, so in this case the work done is = 10N X 20m which is 200 Nm.
B. Kenetic Energy is = 1/2 MV^2. So we need to find V. Velocity final^2 = Velocity initial^2 + 2AD. Force = Mass x Acceleration, so the acceleration of the mass is = 10N/2kg = 5kg*m/s^2. Assuming the mass started at rest then you can solve for the final velocity as being = the square root (2 x 5kg*m/s^2 x 20m) = 14.14m/s
So K.E. = 1/2 x 2kg x (14.14m/s)^2 = 199.94J
2007-02-08 04:31:03 · answer #2 · answered by Brian 1 · 0⤊ 0⤋