A 20 kg cart is moving to the right at 5 m/s when it collides elastically with a 45 kg cart that is at rest. After the collision the 20 kg cart is moving to the left at 1.5 m/s. What is the final speed and direction of the 45 kg cart?

the bal will not change its velocity.

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.

the right answer is 0.3 meters per second