Question

a car weighing 1500 kg moving with a velocity of 60 km/ h retards uniformly to rest in 20 sec. find the change in momentum that takes in 1 sec

Answer 1

a= 25m/s2
change in momentum=25*1500

Answer 2

$\textbf{\underline{\underline{According\:to\:the\:Question}}}$

★Given :-

m = 1500 kg

u = 60 km/h

★Change km/h into m/s

$\tt{\rightarrow\dfrac{60\times 1000m}{60\times 60s}}$

= 16.67 m/s

v = 0 km/h

★In m/s = 0 m/s

$\tt{\rightarrow Rate\;of\;change\;in\;momentum=\dfrac{mv-mu}{t}}$

$\tt{\rightarrow\dfrac{m(v-u)}{t}}$

★In 1 second

$\tt{\rightarrow\dfrac{1500\times(0-16.67}{20s}}$

$\tt{\rightarrow\dfrac{1500\times(-16.67}{20}kg/s^{2}}$

= - 1250.2 N

$\text{Negative\;sign\;indicates\;momentum\;is\; decreasing}$

$\boxed{\begin{minipage}{11 cm} Additional Information \\ \\ \ Final\;Velocity=Initial\; velocity+Acceleration\times Time \\ \\ Momentum = Mass\times Velocity \\ \\ Force=Mass\times Acceleration \\ \\ Force = \dfrac{Change\;in\;Momentum}{Time\;Interval} \\ \\ Impulse = Force\times Time \end{minipage}}$