Question

a frictionless cart with a mass of 12.0 kg is rolling at a velocity of 0.960 m/s n. what is the final kinetic energy of the cart if it is acted on by a force of 56.0 n n over a displacement of 2.60 m n?
151 j
146 j
162 j
140 j

Explanation:

Step1: Calculate initial kinetic energy

$KE_i = \frac{1}{2}mv_i^2 = \frac{1}{2}(12.0\ \text{kg})(0.960\ \text{m/s})^2$
$KE_i = \frac{1}{2}(12.0)(0.9216) = 5.5296\ \text{J}$

Step2: Calculate work done by force

$W = Fd = (56.0\ \text{N})(2.60\ \text{m}) = 145.6\ \text{J}$

Step3: Find final kinetic energy

$KE_f = KE_i + W = 5.5296\ \text{J} + 145.6\ \text{J}$
$KE_f \approx 151.13\ \text{J}$

Answer:

151 J