Newton's Laws And Applications Quiz

To cause a mass at rest to move, a force must be applied. Force is a physical quantity that can cause a change in the state of motion of an object. In this case, the force will overcome the inertia of the mass and initiate its movement. Without the application of force, the mass will remain at rest due to the principle of inertia. Therefore, force is necessary to cause the mass to move.

When you push a car forward, there are multiple forces acting on you. The car pushes back on you with an equal and opposite force according to Newton's third law of motion. Gravity pulls you down towards the ground. The ground pushes up on you with a normal force to counteract gravity. Additionally, the friction between your shoes and the ground pushes you forward, providing the necessary force to move the car.

The SI units of force are called Newtons. This is because the Newton is the standard unit of force in the International System of Units (SI). It is named after Sir Isaac Newton, a renowned physicist who made significant contributions to the field of mechanics and the study of forces. The Newton is defined as the force required to accelerate a one-kilogram mass by one meter per second squared. Therefore, Newtons is the correct answer.

The correct answer explains that the reason why you don't sink to the middle of the earth despite gravity pulling you down is because the ground applies an upward force on you that is equal to the downward force of gravity. This upward force counteracts the pull of gravity and prevents you from sinking further into the earth.

When you push on a wall with a force of 30 N, according to Newton's third law of motion, the wall exerts an equal and opposite force of 30 N on you. This means that the wall pushes back on you with the same force of 30 N.

Acceleration is the correct answer because it refers to the change in velocity over time. Velocity is a vector quantity that includes both speed and direction, so when there is a change in velocity, it means there is a change in either speed, direction, or both. Acceleration can be positive (speeding up), negative (slowing down), or zero (constant velocity). It is measured in units of distance per time squared, such as meters per second squared (m/s²).

Displacement refers to the change in position of an object. It is a vector quantity that takes into account both the magnitude and direction of the change. Velocity, on the other hand, refers to the rate at which an object changes its position. While velocity is related to displacement, it specifically focuses on the change in position over time. Rate is a general term that can refer to various types of changes, but in this context, displacement is the most appropriate term to describe the change in position.

Inertia is the property of mass that resists changes in velocity. It refers to the tendency of an object to stay at rest or in motion unless acted upon by an external force. This property is directly related to the mass of an object, with larger masses having greater inertia. Inertia is a fundamental concept in physics and is responsible for many everyday phenomena, such as the difficulty in starting or stopping a moving object.

When traveling at a constant speed in one direction, the forces acting on you are balanced by equal forces from the opposite direction. This is because the net force on an object moving at a constant speed is zero. In order to maintain a constant speed, the forces pushing you forward must be balanced by the forces pushing you backward. Therefore, all forces acting on you are balanced by equal forces from the opposite direction.

When you jump into the air, the correct explanation is that the floor pushes back on you as a reaction to you pushing down on the floor. This is due to Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. When you push down on the floor with your muscles, the floor exerts an equal and opposite force, pushing you up into the air.