If two forces of equal strength act on an object in opposite directions, the forces will cancel, resulting in a net force of zero and no movement. equal to the sum of the two forces. When two unequal forces act in opposite directions on an object, the net force is the difference of the two forces.

balanced forces: forces that are equal in size and opposite in direction. Balanced forces do not result in any change in motion.

If two forces act on an object in the same direction, the net force is equal to the sum of the two forces. This always results in a stronger force than either of the individual forces alone.

When two forces acting on an object are equal in size but act in opposite directions, we say that they are balanced forces .

Examples of balanced forces:

• The weight of an object and the normal force acting on a body are balanced.
• A car that is pushed from opposite sides with equal force.
• A lizard on a wall in a vertical position.
• A ball hanging by a rope.
• A weighing balance where the weight in both of the pans is exactly equal.

Examples of unbalanced forces

• Kicking a soccer ball.
• The up and down movement in a seesaw.
• The taking-off of a Rocket.
• Skiing along the mountain slopes.
• Hitting a baseball.
• A turning vehicle.
• Drowning of an object.
• Apple falling on the ground.

If you push against a wall, the wall pushes back with an equal but opposite force. Neither you nor the wall will move. Forces that cause a change in the motion of an object are unbalanced forces.

In science, a force is a push or a pull. All forces have two properties: direction and magnitude.

When we push or pull an object we can make it move. If we push the car we make it move because our push is greater than the other forces acting upon it. If, on the other hand, an object is moving at a constant speed in a straight line then again the forces are said to be balanced.

If an object such as a toy car is given a push across a flat surface, there is initially a forward force acting on it; however, once it is allowed to move freely, there is no forward force. Friction exerts a force in the opposite direction to the object’s motion and is the reason it eventually stops moving.

The strong nuclear force, also called the strong nuclear interaction, is the strongest of the four fundamental forces of nature. It’s 6 thousand trillion trillion trillion (that’s 39 zeroes after 6!) times stronger than the force of gravity, according to the HyperPhysics website.

An unbalanced force is an unopposed force that causes a change in motion. A net force = unbalanced force. If however, the forces are balanced (in equilibrium) and there is no net force, the object will not accelerate and the velocity will remain constant.

If you kick a football and it moves from one place to another, it means that unbalanced forces are acting upon it. Ball moves from one place to another after kicking it. This is an example of unbalanced force.

The net force on the object will be zero. The object will keep moving with uniform velocity, if it was moving, or keep standing still when it wasn’t moving. To decelerate you need to apply a positive net force just long enough to bring the velocity down to zero.

The force stopping the object’s motion might be an obvious one – the ground! Friction is a force that slows or stops motion. Friction is the resistance to motion created by two objects rubbing against each other (the sled and the snow, for instance). Even air causes friction.

The force needed to stop the car in 50 metres is 5,000 N.

Once you are moving the same speed as the wind, it is no longer applying any force to you, because you are at rest with respect to the wind. When you say that the acceleration caused by braking a car is “negative”, what you really mean is that its direction is opposite to the direction of motion.

To stop an object means to change its kinetic energy to zero. So, if the initial kinetic energy is 30 J, then the change in kinetic energy has to be 0 – 30 = –30 J. By the work–energy theorem, Wtotal = ΔK, the total amount of work that would be required is –30 J.

Force used to stop the bus = mass of the bus in kg× deceleration = 5000 kg× – 2 m/s² = – 10,000 N.

The kinetic energy of a bus (or any other vehicle) is converted mainly into heat and sound by the break system.

Kinetic energy is directly proportional to the mass of the object and to the square of its velocity: K.E. = 1/2 m v2. If the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters squared per second squared.

Will the ball return to the same point or will her chin be in danger? Explain. The chin will be in great danger! The kinetic energy added by the push increases the total energy of the system, so the ball will swing back farther.

What is the total work done by the 50-N force? = 160 J. Kinetic energy is the energy associated with an object’s motion.

Work is the measure of energy transfer when a force (F) moves an object through a distance (d). So when work is done, energy has been transferred from one energy store to another, and so: energy transferred = work done.

The object moves in such a way that the point of application of the force remains fixed (dx=0). …

Power is a measure of the amount of work that can be done in a given amount of time. Power equals work (J) divided by time (s). The SI unit for power is the watt (W), which equals 1 joule of work per second (J/s).