Question 135: Motion in 2D & Vectors

Question

A projectile is given an initial velocity of $$\left( {\widehat i + 2\widehat j} \right)$$ m/s, where $${\widehat i}$$ is along the ground and $${\widehat j}$$ is along the
vertical. If g = 10 m/s
2
, the equation of its trajectory is:

Accepted Answer

$$\overrightarrow u  = \widehat i + 2\widehat j = {u_x}\widehat i + {u_y}\widehat j$$
$$ \Rightarrow u\cos 	heta  = 1,u\sin 	heta  = 2$$
Also $$x = {u_x}t$$ and
$$y = {u_y}t - {1 \over 2}g{t^2}$$
$$ \Rightarrow $$ $$y = x	an 	heta  - {1 \over 2}{{g{x^2}} \over {u_x^2}}$$
$$	herefore$$ $$y = 2x - {1 \over 2}g{x^2} = 2x - 5{x^2}$$

Answer

y = x - 5x
2

Answer

y = 2x - 5x
2

Answer

4y = 2x - 5x
2

Answer

4y = 2x - 25x
2

Motion in 2D & Vectors

A projectile is given an initial velocity of $\left( {\widehat i + 2\widehat j} \right) m/s, where {\widehat i} is along the ground and {\widehat j}$ is along the vertical. If g = 10 m/s 2 , the equation of its trajectory is:

Choose the correct answer: