HELP ASAPPP An object of mass m is moving along a frictionless track with known speed vo to the right. It collides with and sticks to an object of mass 4m moving with known speed v2 to the right. Considering the law of conservation and the law of conservation of momentum and conservation of mechanical energy, must be applied to determine the final speed of the carts, and why?
a
Both conservation of mechanical energy and conservation of momentum, because neither cart changes direction.
b
Only conservation of momentum, because the momentum lost by one cart is gained by the other and there is only one unknown quantity.
c
Either conservation of momentum or conservation of mechanical energy, because only one equation is required to solve for the one unknown variable.
d
Both conservation of mechanical energy and conservation of momentum, because both principles apply in any collision.

The ballistic pendulum was invented in 1742 by english mathematician benjamin robins. it consists of an initially stationary pendulum that moves after being struck by a bullet, and it is used to measure the original velocity of the bullet. the known variables are the bullet's mass m, the pendulum's mass m, and the height to which the block and bullet swing, determined by the length of the pendulum l and final angle θ. two principles of physics are necessary to solve for the bullet's original velocity. what are these principles? conservation of momentum and newton's third law conservation of energy and conservation of angular momentum grade summary deductions 0% potential 100% conservation of momentum and newton's second law. newton's second law and conservation of angular momentum. conservation of energy and newton's third law conservation of momentum and conservation of angular momentum. conservation of momentum and conservation of energy conservation of energy and newton's second law.

What are the factors that affect the resistance of a wire?

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up