Answer:
320 N/m
Explanation:
From Hooke's law, we deduce that
F=kx where F is applied force, k is spring constant and x is extension or compression of spring
Making k the subject of formula then

Conversion
1m equals to 100cm
Xm equals 25 cm
25/100=0.25 m
Substituting 80 N for F and 0.25m for x then

Therefore, the spring constant is equal to 320 N/m
Answer:
we need to see the answers but probably 1 or -1
(a) This is a freefall problem in disguise - when the ball returns to its original position, it will be going at the same speed but in the opposite direction. So the ball's final velocity is the negative of its initial velocity.
Recall that

We have
, so that

(b) The speed of the ball at the start and at the end of the roll are the same 8 m/s, so the average speed is also 8 m/s.
(c) The ball's average velocity is 0. Average velocity is given by
, and we know that
.
(d) The position of the ball
at time
is given by

Take the starting position to be the origin,
. Then after 6 seconds,

so the ball is 42 m away from where it started.
We're not asked to say in which direction it's moving at this point, but just out of curiosity we can determine that too:

Since the velocity is positive, the ball is still moving up the incline.
Answer:
It will take about 1.32 seconds to travel to his location.
Explanation:
Considering the sound travels at 340 m/s, then if a person is at a distance of 450 m m from the bell, we can use the velocity formula to find the answer;

Answer:
The ban was intended to prevent the imminent extinction of ospreys, peregrine falcons, and bald eagles, our national bird, among other species; they were vulnerable because DDT caused a fatal thinning of eggshells, which collapsed under the weight of the parent incubating them.
Explanation:
The hidden cost was to control pests was washing off into rivers and streams, poisoning fish, birds, and even humans with toxic chemicals.
Hope this helps