Answer:
v = 21 m / s
Explanation:
We can solve this exercise with the kinematics equations, let's start by finding the acceleration of the train with the initial data
v = v₀ + a t
the initial speed is the speed within the city 6 m / s, the final speed is v = 11 m / s and the time is t = 8 s
a = (v-v₀) / t
a = (11 - 6) / 8
a = 0.625 m / s²
when it leaves the city with speed vo = 11 m / s it accelerates for t = 16 s
v = v₀ + a t
v = 11 + 0.625 16
v = 21 m / s
Answer:
The impulse exerted by one cart on the other has a magnitude of 4 N.s.
Explanation:
Given;
mass of the first cart, m₁ = 2 kg
initial speed of the first car, u₁ = 3 m/s
mass of the second cart, m₂ = 4 kg
initial speed of the second cart, u₂ = 0
Let the final speed of both carts = v, since they stick together after collision.
Apply the principle of conservation of momentum to determine v
m₁u₁ + m₂u₂ = v(m₁ + m₂)
2 x 3 + 0 = v(2 + 4)
6 = 6v
v = 1 m/s
Impulse is given by;
I = ft = mΔv = m(
The impulse exerted by the first cart on the second cart is given;
I = 2 (3 -1 )
I = 4 N.s
The impulse exerted by the second cart on the first cart is given;
I = 4(0-1)
I = - 4 N.s (equal in magnitude but opposite in direction to the impulse exerted by the first).
Therefore, the impulse exerted by one cart on the other has a magnitude of 4 N.s.
Answer:
a) 9.0
Explanation:
The force between two point charges, obeys Coulomb's Law, which can be written as follows:

As it can be seen, if the separation between the charges remains the same, the new value of the force will be directly proportional to the product of the charges.
If both charges are tripled, the mutual force between them will be changed in a factor equal to 3.0*3.0 = 9.0