Physics2

• Jan 12th 2008, 10:19 AM
johett
Physics2
A bomber in level flight, flying at 92m/s, releases a bomb at a height of
1950m.

a)how long is it before the bomb strikes the earth?
b)how far does it travel horizontally?
c)what are the horizontal and vertical components of its velocity when it strikes?
d)what is its velocity of impact?

-thanks!
• Jan 12th 2008, 06:53 PM
mr fantastic
Quote:

Originally Posted by johett
A bomber in level flight, flying at 92m/s, releases a bomb at a height of
1950m.

a)how long is it before the bomb strikes the earth?
b)how far does it travel horizontally?
c)what are the horizontal and vertical components of its velocity when it strikes?
d)what is its velocity of impact?

-thanks!

You're probably told to ignore air resistance. Then all questions use the straight-line motion formulae under constant acceleration, applied as required in the horizontal and vertical components of the motion of the bomb.

a) Vertical component: Take downwards as positive. u = 0 m/s, y = 1950 m, a = g = either 9.8 or 10 m/s^2 (use the value you've been told to use), t = ?

b) Horizontal component: u = 92 m/s, a = 0 m/s^2, t = get from (a), x = ?

c) Vertical component: Take downwards as positive. u = 0 m/s, y = 1950 m, a = g = either 9.8 or 10 m/s^2 (use the value you've been told to use), $\displaystyle v_y = ?$

Horizontal component: u = 92 m/s, a = 0 m/s^2, t = get from (a), $\displaystyle v_x = ?$

d) Speed: $\displaystyle v^2 = v_x^2 + v_y^2$.
Direction: At an angle $\displaystyle \theta = \tan^{-1}\left( \frac{v_y}{v_x} \right)$ to the horizontal. Do you see why?

Question of related interest (either now or very soon): Question 2 of this thread.