Explanation:
Here we will apply the law of conservation of momentum which is one of the powerful laws of physics. As this law states that the "if no external forces are acting on the system then the net momentum of the system before and after must remain conserved. As the astronaut has a hammer, if he throws it in the direction opposite of his space craft, he will automatically move towards the space craft to conserve the momentum. That's how he can reach the space craft easily by throwing away the hammer.
The solution for this problem is:
Let u denote speed.
Equating momentum before and after collision:
= 0.060 * 40 = (1.5 + 0.060) u
= 2.4 = 1.56 u
= 2.4 / 1.56 = 1.56 u / 1.56
= 1.6 m / s is the answer for this question. This is the speed after the collision.
aumenta su velocidad de 60 a 100 Km/h en 20 segundos. Calcular la fuerza resultante que actúa sobre el coche y el espacio recorrido en ese tiempo
Not sure this is a physics question (probably biology).
Anyway, the correct answer is A):
"Plasticity helps us to adapt to our environment. It also generally decreases with age".
Plasticity is the ability to adapt to the environment. Since this ability is linked with brain functions, and brain functions worsen with age, then plasticity decreases with age.
