Question

Plz help me guys........​

Answer 1

Answer:

$here$

$mass \: of \: the \: car$

$m = 1500 \: kg$

$initial \: velocity$

$u = 30 \: km {h}^{ - 1}$

$= \frac{30 \times 1000 \: m}{60 \times 60 \: s}$

$\frac{25}{3} m {s}^{ - 1}$

$final \: velocity$

$v = 60 \: km \: {h}^{ - 1}$

$= \frac{60 \times 1000 \: m}{60 \times 60 \: s}$

$= \frac{50}{3} m {s}^{ - 1}$

Now,

The initial Kinetic energy of the car ,

$ek1 = \frac{1}{2} m {u}^{2}$

$= \frac{1}{2} \times 1500 \times ( { \frac{25}{3}) }^{2}$

$= \frac{1}{2} \times 1500 \times \frac{25}{3} \times \frac{25}{3}$

$= \frac{250 \times 25}{3}$

$\frac{156250}{3}j$

Similarly, final Kinetic energy of the car,

EK1 = 1/2 mv²

= 1/2 × 1500 × (50/3)²

= 1/2 × 1500 × 50/3 × 50/3

= 250 × 2500 ÷ 3

= 625000 / 3 J

Thus, the work done = change in Kinetic energy.

$= ekf - eki$

$= \frac{625000 - 156250}{3}$

$= \frac{468750}{3}$

$= 156250j$

Answer 2

$\huge\bigstar\underline\mathfrak\pink{Answer:-}$

$\large\sf\red{Given:-}$

$\sf{mass\:of\:the\:car}$ = $\sf{1500\:kg}$

$\sf{initial\:velocity}$ = $\sf{30kmh}$

$\longrightarrow$$\sf\frac{30 \times 1000m}{60 \times 60s}$

$\longrightarrow$$\sf\frac{30}{3} ms$

$\sf{final\:velocity}$ = $\sf{60km\:h}$

$\longrightarrow$$\sf\frac{60 \times 1000m}{60 \times 60s}$

$\longrightarrow$$\sf\frac{50}{3} ms$

$\sf\green{Now,}$

$\sf{the\:initial\:kinetic\:energy\:of\:the\:car}$

$\sf{ek1}$ = $\sf\frac{1}{2}$ $\sf{mu}^{2}$

$\longrightarrow$$\sf\frac{1}{2} × 1500 × \frac{25}{3} × \frac{25}{3}$

$\longrightarrow$$\sf\frac{250×50}{3}$

$\longrightarrow$$\sf\frac{156250}{3}$j

$\sf\red{Similarly,}$

$\sf{Final\:kinetic\:energy\:of\:the\:car}$

$\sf{ek1}$ = $\sf\frac{1}{2}$ $\sf{mv}^{2}$

$\longrightarrow$$\sf\frac{1}{2} × 1500 × \frac{50}{3} × \frac{50}{3}$

$\longrightarrow$$\sf\frac{250×2500}{3}$

$\longrightarrow$$\sf\frac{625000}{3}$j

$\sf\orange{Thus,}$

$\sf{the\:work\:done=change\:in\:Kinetic\:energy}$

$\longrightarrow$$\sf{ekf-eki}$

$\longrightarrow$$\sf\frac{625000-156250}{3}$

$\longrightarrow$$\sf\frac{468750}{3}$

$\longrightarrow$$\sf{156250\:j}$