A truck moves with a certain momentum. If both its speed and its mass are doubled, how much greater is its momentum?

A) Two times.
B) Four times.
C) Eight times.
D) Unchanged, the same.

M = mV.

M = 2m*2V = 4mV.
Therefore the ans. is B.

To find the increase in momentum, we need to understand the relationship between momentum, speed, and mass. The momentum of an object is defined as the product of its mass and its velocity (speed in a given direction).

Mathematically, momentum (p) is given by the equation:
p = m * v

Where:
p = momentum
m = mass
v = velocity (speed)

In this case, the truck's speed and mass are both doubled. Let's assume the initial momentum of the truck is p_initial.

When the speed is doubled, the new speed (v_new) becomes 2 times the initial speed.
So, v_new = 2 * v_initial.

When the mass is doubled, the new mass (m_new) becomes 2 times the initial mass.
So, m_new = 2 * m_initial.

Now, we can calculate the new momentum (p_new) using the equation:
p_new = m_new * v_new

Substituting the values we have:
p_new = (2 * m_initial) * (2 * v_initial)
= 4 * (m_initial * v_initial)
= 4 * p_initial

Therefore, the new momentum (p_new) is four times (4x) the initial momentum (p_initial).

So, the correct answer is:
B) Four times.