A 2-kilogram block slides along a horizontal, frictionless surface at 5.0 meters per second for 4 seconds. The magnitude of the block’s momentum is

momentum = mass * velocity

To find the magnitude of the block's momentum, we need to use the formula for momentum:

Momentum (p) = mass (m) × velocity (v)

Given that the mass of the block is 2 kilograms and the velocity is 5.0 meters per second, we can calculate the momentum:

p = m × v
p = 2 kg × 5.0 m/s
p = 10 kg·m/s

So, the magnitude of the block's momentum is 10 kg·m/s.