Question

always use significant figure rules. remember that these rules apply to all numbers that are measurements. a 2,000 - kg test car, traveling 60 m/s hits a brick wall. using motion pictures, the time involved is determined to be 0.050 s. what is the change in momentum of the car? kg·m/s +1.2 x 10^5 -1.2 x 10^5

Explanation:

Step1: Identificar la fórmula del momento

El momento lineal $p = mv$. El cambio en el momento $\Delta p=p_f - p_i$. Como el coche se detiene ($v_f = 0$), $\Delta p=0 - mv_i=-mv_i$.

Step2: Sustituir valores dados

Dado que $m = 2000$ kg y $v_i=60$ m/s.
$\Delta p=- (2000\ \text{kg})\times(60\ \text{m/s})=- 120000\ \text{kg}\cdot\text{m/s}=-1.2\times 10^{5}\ \text{kg}\cdot\text{m/s}$

Answer:

$-1.2\times 10^{5}$