Answer to Question #104549 in Mechanics | Relativity for havefun7741

Question

https://upload.cc/i1/2020/03/03/UFc9i5.jpg

d8 is 4

Answer 1

i)

$$u=\frac{d}{T}=\frac{40+80+60}{5+4+3}=15\frac{m}{s}$$

ii)

$$\bold{s}=(40\cos{30}\bold{i}-40\sin{30}\bold{j})+80\bold{i}+\\+(60\cos{50}\bold{i}+60\sin{50}\bold{j})$$

$$\bold{s}=(153\bold{i}+26\bold{j})\ m$$

iii)

$$\bold{v}=\frac{(153\bold{i}+26\bold{j})}{5+4+3}=(12.8\bold{i}+2.2\bold{j})\frac{m}{s}$$

iv)

$$v=\sqrt{12.8^2+2.2^2}=12.9\frac{m}{s}$$

$$\theta=\arctan{\frac{2.2}{12.8}}=9.6\degree$$