Physics Challenge for Grade 9

What is the formula for calculating speed?

• Speed = Time / Distance

• Speed = Distance + Time

• Speed = Distance - Time

• Speed = Distance / Time

Define Newton's First Law of Motion.

• An object will remain at rest or in uniform motion unless acted upon by an external force.

• An object will accelerate unless a force is applied.

• An object will change direction only if a force is applied.

• An object will remain in motion only if it is in a vacuum.

What is the unit of force in the International System of Units?

• joule (J)

• watt (W)

• newton (N)

• pascal (Pa)

Explain the concept of kinetic energy.

• Kinetic energy is the energy of an object in motion, calculated as KE = 1/2 mv^2.

• Kinetic energy is the energy released during a chemical reaction.

• Kinetic energy is the energy stored in an object at rest.

• Kinetic energy is the energy required to lift an object against gravity.

What is the difference between mass and weight?

• Mass and weight are the same thing; they both measure how heavy something is.

• Weight is the amount of matter; mass is the force of gravity on that matter.

• Mass is the weight of an object; weight is the mass of an object.

• Mass is the amount of matter; weight is the force of gravity on that mass.

State the law of conservation of energy.

• Energy can be created and destroyed.

• Energy can only be created from matter.

• Energy is always lost in transformations.

• Energy cannot be created or destroyed, only transformed.

How does friction affect motion?

• Friction only affects stationary objects.

• Friction opposes motion, slowing down or stopping moving objects.

• Friction has no effect on motion.

• Friction increases the speed of moving objects.

What is the formula for calculating gravitational potential energy?

• U = mv^2

• U = 1/2 kx^2

• U = Fd

• U = mgh

Describe the relationship between voltage, current, and resistance.

• Voltage is the same as current.

• Voltage, current, and resistance are related by Ohm's Law: V = I * R.

• Resistance increases with higher current only.

• Voltage and resistance are independent of each other.

What is the principle of buoyancy?

• An object submerged in a fluid experiences a downward force equal to the weight of the object itself.

• Buoyancy is the force that pulls objects down in a fluid.

• An object submerged in a fluid experiences an upward buoyant force equal to the weight of the fluid displaced.

• An object in a fluid will always sink regardless of its density.