how do I do this?

Question

A rock thrown horizontally from the top of a radio tower lands 17.0 m from the base of the tower. If the speed at which the object was projected was 9.50 m/s, how high is the tower?

Answer 1

Draw a picture showing the building and the place were the object landed.
||
||
||
______17.0m
Draw 2 force vectors

||---9.50m/s----
|| 9.814m/s^2
|| |/
______17.0m
Find out how long it took the object to hit the ground. 17.0m/9.50m/s=1.789s
Find out how far the object fell
9.814m/s^2*(1.789s)^2=31.43m
Lucky for you this problem takes place in a phisics book with no wind resistence or distance from the top of the tower.

Answer 2

Okay, it's to do with vectors.

1. The rock is being pulled by gravity straight down at 9.81 m/s^2
2. The rock is traveling at 9.5 m/s horizontaly.
3. It lands 17 meters out.


Here's how you work it out:

1. How long does it take something traveling 9.5 m/s horitontaly to go 17 meters?
2. If something accelerates for that long at 9.81 m/s^2, how far will it go?

Answer 3

Using the basic assumptions of textbook physics, there is no air drag on the rock. So figure out how long the rock took to hit the ground (i.e. how long it was in the air). If it travelled at 9.5 m/s for 17m, it must have been in the air for 1.79s.

Now that you know that, you can figure out how far it fell at 9.8 m/s^2.

Answer 4

assuming no angle of elevation... all initial velocity is in x direction...
x=(9.5m/s) * t
y=(-9.8m/s) * (t^2) + h

t is time in seconds
h is initial height


set x=17m for the horizontal distance travelled and solve for t to find the time it takes to reach 17m.

set y=0 since the object will be at the ground when it lands after t seconds. plug in the t value obtained and solve for h.

that will give you the inital height.

Answer 5

sorry dont know, dont care, but thanks for the 2 pts
p.s. I love the Pittsburgh Steelers