A100-kg running back runs at 5 m/s into a stationary linebacker. it takes 0.5 s for the running back to be completely stopped. find the magnitude of force exerted on the running back during the collision.

When a 5.0kg cart undergoes a 2.2m/s increase in speed, what is the impulse of the cart

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 790 n/m. it is initially at rest on an inclined plane that is at an angle of 28 degrees with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is k = 0.14. in the initial position, where the spring is compressed by a distance of a = 0.18 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. b) if the spring pushes the block up the incline, what distance, l, in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.

What will a positive and a negative charge do if they are separated from each other?