At the point of maximum displacement (a), the elastic potential energy of the spring is maximum:

while the kinetic energy is zero, because at the maximum displacement the mass is stationary, so its velocity is zero:

And the total energy of the system is

Viceversa, when the mass reaches the equilibrium position, the elastic potential energy is zero because the displacement x is zero:

while the mass is moving at speed v, and therefore the kinetic energy is

And the total energy is

For the law of conservation of energy, the total energy must be conserved, therefore

. So we can write

that we can solve to find an expression for v:
Answer:
d = 44.64 m
Explanation:
Given that,
Net force acting on the car, F = -8750 N
The mass of the car, m = 1250 kg
Initial speed of the car, u = 25 m/s
Final speed, v = 0 (it stops)
The formula for the net force is :
F = ma
a is acceleration of the car

Let d be the breaking distance. It can be calculated using third equation of motion as :

So, the required distance covered by the car is 44.64 m.
Answer:
13 km
Explanation:
The bird flies from the runner, to the finish line, and back to the runner. We can write two equations for the distance it travels:
d = 7.8 km + 7.8 km − 4.9 km/hr × t
d = 24.5 km/hr × t
Solve for t in the second equation and substitute into the first:
t = d / 24.5
d = 7.8 + 7.8 − 4.9 (d / 24.5)
d = 15.6 − 0.2 d
1.2 d = 15.6
d = 13
The bird flies a cumulative distance of 13 km.
They are all classified in the same kingdom