Thursday

April 24, 2014

April 24, 2014

Posted by **Farah** on Sunday, December 5, 2010 at 5:18pm.

Ans: I tried the range formula - (Vi)^2* sin2theeta/(9.81), however i do not get the answer of 4.4m. i get 35.3m, where am i going wrong?

- Physics - check this work for horizontal displacem -
**MathMate**, Sunday, December 5, 2010 at 5:55pmThe range formula applies to an unobstructed projectile. In this case, the project has had an impact (with the water melon), and transfer of momentum has taken place, so the range formula does not apply.

You would have to calculate each step separately to find the final answer. The intermediate unknowns are:

- the horiz. velocity, v0, of the arrow

- the height of the water melon, h

- the combined horizontal velocity, V, after impact with the water melon

- the time, t, it takes for the water melon to drop from a height of h.

- Finally, the horizontal distance travelled during time t with the combined velocity of V.

Assume no air resistance.

Horizontal velocity,V0, of arrow

= v0*cos(θ)

= 20*cos(60°)

= 10 m/s

Vertical velocity of arrow, vy

= 20*sin(θ)

= 17.3 m/s

Highest point attained by arrow, h, can be solved from:

mgh = (1/2)m*vy²

h=m*vy²/mg = 15.3 m.

When the arrow hits the melon, the combined velocity can be obtained from conservation of momentum:

mv0=(m+M)V

or

V=mv0/(m+M)

=0.5*10/(0.5+1.5)=2.5 m/s

Time, t, for melon to fall to the ground

can be solved from

(1/2)gt^2 = h

The horizontal distance travelled is then

V*t

=2.5*t

I get 4.41 as distance.

**Related Questions**

PHYSICS - Ms. Anderson shoots an arrow straight up into the air. The arrow ...

Physics! - Ms. Anderson shoots an arrow straight up into the air. The arrow ...

Physics - Mr. Anderson shoots an arrow straight up into the air. The arrow ...

physics - You are watching an archery tournament when you start wondering how ...

physics - an archer at the edge of a cliff fires an arrow from a height of 14.6 ...

physics - an archer at the edge of a cliff fires an arrow from a height of 14.6 ...

physics - You are watching an archery tournament when you start wondering how ...

physics - You are watching an archery tournament when you start wondering how ...

Physics - An arrow is shot at ground level with an initial speed of 50.0 m/s at ...

Physics - An arrow is shot from the top of a building (height of 30 meters). The...