The aerodynamic shape of the nose cone helps prevent air from slowing the rocket. The fins help guide the rocket to fly straight. Finally, the propellant system includes a mixture of fuel and a chemical called an “oxidizer” that gives off oxygen. The fuel and oxidizer burn together to launch the rocket off the ground.

A rocket launches when the force of thrust pushing it upwards is greater than the weight force due to gravity downwards. This unbalanced force causes a rocket to accelerate upwards. A rocket will continue to speed up as long as there is a resultant force upwards caused by the thrust of the rocket engine.

Thrust is the force which moves the rocket through the air, and through space. Thrust is generated by the propulsion system of the rocket through the application of Newton’s third law of motion; For every action there is an equal and opposite re-action.

The reaction is the movement of the rocket in the opposite direction. To enable a rocket to lift off from the launch pad, the action, or thrust, from the engine must be greater than the mass of the rocket. In space, however, even tiny thrusts will cause the rocket to change direction.

Section Summary

1. The greater the exhaust velocity of the gases, the greater the acceleration.
2. The faster the rocket burns its fuel, the greater its acceleration.
3. The smaller the rocket’s mass, the greater the acceleration.

Because propellant is burned up, the mass of the rocket changes during flight. Its mass is the sum of all its parts. Thus the rocket’s mass smaller during flight. In order for the left side of our equation to remain in balance with the right side, acceleration of the rocket has to increase as its mass decreases.

Newton’s second law

Acceleration (a) is the change in velocity (Δv) over the change in time (Δt), represented by the equation a = Δv/Δt. This allows you to measure how fast velocity changes in meters per second squared (m/s^2). Acceleration is also a vector quantity, so it includes both magnitude and direction.

A newton is the SI unit of force. An unbalanced force of 1 N will accelerate a mass of 1 kg at 1 m/s2. One Newton of force is equal to one kilogram-meter per second per second (1kg-m/s2).

The first equation shows that, after one second, an object will have fallen a distance of 1/2 × 9.8 × 12 = 4.9 m. After two seconds it will have fallen 1/2 × 9.8 × 22 = 19.6 m; and so on.

An object with negative acceleration could be speeding up, and an object with positive acceleration could be slowing down. And if the acceleration points in the opposite direction of the velocity, the object will be slowing down.

3 Answers. Constant acceleration means that the acceleration does not change. Some would say that if the acceleration is zero then the acceleration does not change and so one can say that the acceleration is constant.

Answer: Yes, an object can have zero velocity and still be accelerating simultaneously. Let us consider an object moving in the forward direction.

If the velocity of the particle changes at a constant rate, then this rate is called the constant acceleration. For example, if the velocity of a particle moving in a straight line changes uniformly (at a constant rate of change) from 2 m/s to 5 m/s over one second, then its constant acceleration is 3 m/s2.

In the middle of the journey, while the velocity remains constant, the position changes at a constant rate. This shows the velocity of the object over time. The object’s velocity increases in the beginning as it accelerates at the beginning, then remains constant in the middle before it slows down toward the end.

If acceleration is constant, then the velocity will change by a constant amount every second, in other words: velocity is NOT constant.

When an object is speeding up, the acceleration is in the same direction as the velocity. Thus, this object has a positive acceleration. In Example B, the object is moving in the negative direction (i.e., has a negative velocity) and is slowing down.

If velocity is 0 , that means the object is not moving, but with acceleration present, there is a force acting on the object. Velocity slows to a halt, but is subjected to an acceleration of 9.8 ms2 [down] .

Yes. Anytime the velocity is constant, the acceleration is zero. For example, a car traveling at a constant 90 km/h in a straight line has nonzero velocity and zero acceleration. Its acceleration will change in magnitude and direction as the elevator starts and stops.

Velocity arises from a vector (displacement) while speed arises from a scalar (distance), hence Velocity is a vector (magnitude and direction) and speed is a scalar (magnitude only). When measuring speed the direction of travel is not taken into account. Speed is the rate at which an object covers a specified distance.