Question

A deer is running from a mountain lion when it encounters a fence that is 1.50 m high. Seeing the fence, the deer jumps, leaving the ground at a speed of 13.0 m/s and angle of 29.0º when it is a distance of 2.50 m from the fence. (a) By how much does the deer either clear or miss clearing the fence? (b) Just before reaching the fence, is the deer rising or falling through the air?

Answer 1

Answer:

Explanation:

Given

Initial Velocity (u)=13 m/s

angle$=29^{\circ}$

distance between fence and deer=2.5 m

We consider deer jump similar to projectile motion

equation of trajectory

$y=xtan\theta -\frac{gx^2}{2u^2(cos\theta )^2}$

$y=2.5tan(29)-\frac{9.8\times 2.5^2}{2\times 13^2\times (cos29)^2}$

$y=1.385-0.2368=1.148 m$

Thus deer will cross the fence with an difference in its jump and fence

1.5-1.148=0.351 m

$h_{max}=\frac{u^2sin^2\theta }{2g}$

$h_{max}=\frac{13^2\times (sin29)^2}{2\times 9.8}$

$h_{max}=2.02 m$

so deer rises during when it is over fence