Physics of Mass and Momentum

Mass measures the amount of matter in a body and is measured using an electronic balance.

The SI unit of mass is the kilogram (kg).

Momentum is the product of mass and velocity, calculated using the formula p = mass × velocity.

<p>The momentum is 280 kg·m/s west.</p> Signup and view all the answers

<p>In a closed system, total momentum before an interaction equals total momentum after.</p> Signup and view all the answers

<p>This is explained by Newton's Third Law.</p> Signup and view all the answers

<p>Momentum is conserved during the collision, with the total momentum before equaling the total momentum after.</p> Signup and view all the answers

<p>It means that momentum has both magnitude and direction, and direction is important in calculations.</p> Signup and view all the answers

<p>The velocity of the yellow puck after the collision is 3 m/s to the right.</p> Signup and view all the answers

<p>Their combined speed after the collision is 4 m/s in the direction the skier was originally moving.</p> Signup and view all the answers

<p>One newton is the force needed to accelerate a 1 kg mass by 1 m/s².</p> Signup and view all the answers

<p>A body remains at rest or continues moving at constant velocity unless acted upon by a resultant external force.</p> Signup and view all the answers

<p>The rate of change of momentum is proportional to the applied force and occurs in the direction of the force.</p> Signup and view all the answers

<p>Impulse is the change in momentum, measured in newton-seconds (Ns).</p> Signup and view all the answers

<p>The gravitational force decreases by a factor of 4.</p> Signup and view all the answers

<p>The Sun’s energy comes from nuclear fusion.</p> Signup and view all the answers

<p>F = ma.</p> Signup and view all the answers

<p>The change in momentum of the ball is 4 Ns.</p> Signup and view all the answers

<p>The acceleration due to gravity varies due to factors such as the Earth's rotation, altitude, and the Earth's shape which is not a perfect sphere, causing uneven mass distribution.</p> Signup and view all the answers

<p>Newton's law of universal gravitation states that every mass attracts every other mass with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between their centers. At twice the Earth's radius, the acceleration due to gravity is $g/4$, equating to $2.45 ext{ m/s}^2$.</p> Signup and view all the answers

<p>The spacecraft continues moving due to inertia, which is the tendency of an object in motion to remain in motion unless acted upon by a force.</p> Signup and view all the answers

<p>Friction is the force that opposes the relative motion of two surfaces in contact. It acts against the car's motion, affecting its acceleration and deceleration based on the surface conditions.</p> Signup and view all the answers

<p>A possible reason for the graph not passing through the origin is the presence of static friction or another force acting on the body before motion begins. To adjust, ensure the apparatus is set up so that all external forces are accounted for, allowing for a true measure of acceleration from a stationary start.</p> Signup and view all the answers

<p>Weight is calculated as $W = mg$, where $m$ is mass and $g$ is the acceleration due to gravity. Mass is a scalar quantity representing the amount of matter, while weight is a vector force acting towards the center of a planet.</p> Signup and view all the answers

<p>Terminal velocity is reached when the downward force of weight equals the upward force of air resistance, resulting in zero net force. At this point, the object falls at a constant speed.</p> Signup and view all the answers

<p>The acceleration due to gravity varies across Earth's surface due to its irregular shape and surface features, which affect the distance from the Earth's center. This variation results in different values of $g$ at different locations.</p> Signup and view all the answers

<p>Friction opposes the motion of sliding surfaces, acting as a resistive force that can slow down or stop moving objects. It also helps provide traction necessary for controlled movement.</p> Signup and view all the answers

<p>The net force is determined by the applied force and the opposing frictional force. This is calculated as $F_{net} = F_{applied} - F_{friction}$.</p> Signup and view all the answers

<p>The acceleration due to gravity can be found using the formula $g = \frac{GM}{r^2}$, where $G$ is the gravitational constant, $M$ is the mass of the Earth, and $r$ is its radius.</p> Signup and view all the answers

<p>In free fall within a vacuum, the weight acts on the object continuously, but since there is no air resistance, all objects fall at the same rate regardless of their mass. This creates a situation where the apparent weight is effectively zero during the fall.</p> Signup and view all the answers

<p>The normal reaction force is crucial as it balances the component of weight acting perpendicular to the inclined surface, affecting how the object moves or remains at rest. It helps in analyzing forces involved in motion on slopes.</p> Signup and view all the answers

<p>The frictional force increases with the weight of the object and varies depending on the texture and materials of the surfaces in contact. Rough surfaces generally produce higher friction than smooth surfaces.</p> Signup and view all the answers

<p>Acceleration due to gravity varies with the distance from the Earth's center and the uneven distribution of mass within the Earth. Surface features, altitude, and Earth's rotation can also cause variations in $g$.</p> Signup and view all the answers

<p>To ensure constant velocity during the experiment.</p> Signup and view all the answers

<p>The mass equals the reciprocal of the slope of the line.</p> Signup and view all the answers

<p>To ensure that changes in acceleration are solely due to the applied force.</p> Signup and view all the answers

<p>The principle of conservation of momentum.</p> Signup and view all the answers

<p>By taking twice the value of the slope of the line of best fit.</p> Signup and view all the answers

<p>Use a dense metal sphere to minimize air resistance and ensure the measuring distance is large.</p> Signup and view all the answers

<p>By applying the conservation of momentum formula: momentum before equals momentum after.</p> Signup and view all the answers

<p>The required force can be calculated using the work-energy principle or kinematic equations.</p> Signup and view all the answers

<p>The net force will be negative, indicating that the trolley will not accelerate forward.</p> Signup and view all the answers

<p>Gas is expelled in the opposite direction to apply thrust and change the spacecraft's momentum.</p> Signup and view all the answers

<p>Momentum is conserved in a collision when the total momentum before the collision equals the total momentum after. For example, in a head-on collision between two identical hockey pucks, if one puck stops, the other will continue moving with the same momentum that the stopped puck had.</p> Signup and view all the answers

<p>As a vector quantity, momentum has both magnitude and direction, meaning that the direction of motion affects calculations. In collisions, the directionality of momentum must be considered to accurately determine the outcome of the interactions.</p> Signup and view all the answers

<p>Momentum is directly proportional to mass and velocity, defined by the equation $p = m \times v$. Therefore, an object with more mass will have greater momentum at the same velocity, indicating that it will require more force to change its state of motion.</p> Signup and view all the answers

<p>When a spacecraft expels gas in one direction, it accelerates in the opposite direction while conserving momentum. The total momentum remains constant, as the momentum gained by the spacecraft is equal and opposite to the momentum lost by the expelled gas.</p> Signup and view all the answers

<p>Controlling the mass impacts momentum since momentum is calculated as the product of mass and velocity ($p = m \times v$). By changing the mass while keeping velocity constant, the momentum of the object will increase or decrease proportionately.</p> Signup and view all the answers

<p>The direction of velocity affects momentum calculations as momentum is a vector quantity; it must consider positive and negative signs according to direction.</p> Signup and view all the answers

<p>The total momentum before a collision equals the total momentum after the collision in a closed system, illustrating the principle of conservation of momentum.</p> Signup and view all the answers

<p>In a frictionless environment, objects will maintain their state of motion; Newton's first law explains that they won't change velocity without an external force.</p> Signup and view all the answers

<p>Newton's second law states that the force acting on an object equals the mass of the object multiplied by its acceleration, represented as F = ma.</p> Signup and view all the answers

<p>Impulse, defined as the product of force and the time duration it acts, results in a change in momentum, helping to explain how forces affect moving objects.</p> Signup and view all the answers