Answer:
v = 2.94 m/s
Explanation:
When the spring is compressed, its potential energy is equal to (1/2)kx^2, where k is the spring constant and x is the distance compressed. At this point there is no kinetic energy due to there being no movement, meaning the net energy in the system is (1/2)kx^2.
Once the spring leaves the system, it will be moving at a constant velocity v, if friction is ignored. At this time, its kinetic energy will be (1/2)mv^2. It won't have any spring potential energy, making the net energy (1/2)mv^2.
Because of the conservation of energy, these two values can be set equal to each other, since energy will not be gained or lost while the spring is decompressing. That means
(1/2)kx^2 = (1/2)mv^2
kx^2 = mv^2
v^2 = (kx^2)/m
v = sqrt((kx^2)/m)
v = x * sqrt(k/m)
v = 0.122 * sqrt(125/0.215) <--- units converted to m and kg
v = 2.94 m/s
d. the rate at which work is accomplished
Answer:
1531 m
Explanation:
The motion of the jet ski is an uniformly accelerated motion, so we can find the distance travelled by using the following suvat equation:
where
s is the distance
u is the initial velocity
t is the time
a is the acceleration
For the jet ski in this problem,
t = 35 s
u = 0 (it starts from rest)
Solving for s, we find the distance travelled:
This is an example of the Newton`s Second Law:
F = m * a
a = F / m
F = 8 N, m = 2 kg.
a = 8 N : 2 kg
Answer:
a = 4 m/s²
