The work to stretch a spring from its rest position is
(1/2) (spring constant) (distance of the stretch)²
E = 1/2 k x² .
You said it takes 1700 joules to stretch the spring 3 meters from its rest position, so we can write
1700 joules = 1/2 k (3m)²
1 joule = 1 newton-meter
1700 N-m = 1/2 k (3m)²
Multiply each side by 2: 3400 N-m = k · 9m²
Divide each side by 9m² k = 3400 N-m / 9m²
= (377 and 7/9) newton per meter
Answer:

Explanation:
The volume of the balloon can be find compared the force in each cases so:
reduce 25% from 74kg

So the net force uproad on the balloon is

Now the density of the both gases air and helium are different however the volume is the same change offcorss the mass so:






By the law of momentum conservation:-
=>m¹u¹ + m²u² = m1v1 + m²v² {let East is +ve}
=>u¹ + u² = v¹ + v² {as m1=m2}
=>3.5 - 2.75 = v1-1.5
<span>
=>v¹ = 2.25 m/s (East) </span>
<h2>
a) Displacement of penny = 1300 i + 2400 j - 640 k</h2><h2>b) Magnitude of his displacement = 2729.47 m</h2>
Explanation:
a) He walks 1300 m east, 2400 m north, and then drops the penny from a cliff 640 m high.
1300 m east = 1300 i
2400 m north = 2400 j
Drops the penny from a cliff 640 m high = -640 k
Displacement of penny = 1300 i + 2400 j - 640 k
b) Displacement of man for return trip = -1300 i - 2400 j

Magnitude of his displacement = 2729.47 m
Answer:

Explanation:
A simple pendulum is a system consisting of a mass attached to a string, and oscillating in a periodic motion, back and forth, along an equilibrium position.
The period of a pendulum is the time it takes for the pendulum to complete one oscillation.
The period of a pendulum is given by the equation

where
L is the length of the pendulum
g is the acceleration due to gravity
From the formula, we see that the period of a pendulum does not depend on the mass.
Therefore, the only 2 factors affecting the period of a pendulum are:
- The length of the pendulum: the longer it is, the longer the period of oscillation
- The acceleration due to gravity: the greater it is, the shorter the period of the pendulum