# Practice Problems for General Physics: Momentum, 1D Collisions, Torque & More

• apaxapax
In summary, momentum is a measure of an object's mass and velocity, while velocity is simply the speed and direction of an object's motion. Collisions affect momentum by following the law of conservation of momentum, where the total momentum before and after the collision must be equal. Torque is a measure of the twisting force applied to an object and is calculated by multiplying the force applied by the distance from the pivot point. An object's moment of inertia can be increased by increasing its mass or changing its shape, and it is a measure of its resistance to rotational motion. Lastly, momentum cannot be negative, but the direction of momentum can change.

#### apaxapax

Hi all,

Just wondering if anyone knows of a good webstite for practice problems. I ve looked around and most sites have one or two problems. Maybe its me but I learn better by doing lots of problems over and over. I am taking general physics and am now working on momentum, 1 d collisions, torque, angular rotation..etc.

Any help would be great.

thanks

## 1. What is the difference between momentum and velocity?

Momentum is a measure of an object's mass and velocity, while velocity is simply the speed and direction of an object's motion. In other words, momentum takes into account both the object's speed and its mass, whereas velocity only describes the object's speed.

## 2. How do collisions affect momentum?

In a collision between two objects, the total momentum before and after the collision must be equal. This means that if one object's momentum increases, the other object's momentum must decrease by the same amount. This is known as the law of conservation of momentum.

## 3. What is torque and how is it calculated?

Torque is a measure of the twisting force applied to an object. It is calculated by multiplying the force applied to the object by the distance from the pivot point to the point where the force is applied. The unit for torque is Newton-meters (Nm).

## 4. How can you increase an object's moment of inertia?

An object's moment of inertia is a measure of its resistance to rotational motion. It can be increased by either increasing the object's mass or by changing its shape to distribute the mass farther from the axis of rotation. A larger moment of inertia means that more torque is needed to produce the same amount of angular acceleration.

## 5. Can you have negative momentum?

No, momentum is a vector quantity and therefore cannot be negative. However, the direction of momentum can change, resulting in a negative or opposite direction. In these cases, the magnitude of the momentum remains the same, but the direction changes.