Physics: Basic 2 (Newton's 2nd law, Resultant forces, speed...)

All objects fall at the acceleration of ___m/s/s downwards. ( write the correct number)

Answer explanation

What is terminal velocity?

• the difference between the final and initial position of a point trajectory

• quantitative measure of inertia

• the steady speed achieved by an object freely falling through a gas or liquid

• representation of both a quantity and a direction at the same time

For an object to accelerate, there must be a ___ _____.

What is the formula linking force, acceleration, and mass?

• F= ma

What is the resultant force on an object that is stationary or moving with constant velocity?

• The resultant force is zero
• The resultant force is equal to the mass of the object
• The resultant force is equal to the acceleration of the object
• The resultant force is equal to the weight of the object

What is speed?

• The rate at which someone or something is able to move or operate
• The distance covered in a unit of time
• The time taken to cover a certain distance
• The force exerted by a moving object

Why does an object reach a terminal velocity?

• Because it runs out of energy
• Because it reaches the maximum speed limit
• Because the gravitational pull decreases
• Because the downward force of gravity equals the upward force of air resistance

Describe how does a parachute slow down a parachutist.

Answer explanation

A parachute slows down a parachutist by creating more air resistance or drag. Air resistance is a force that opposes the motion of an object through the air. The more surface area an object has, the more air resistance it creates.

The parachute also changes the shape of the parachutist, making them more like a feather than a stone. A feather falls more slowly than a stone because it has more air resistance per unit mass. A parachutist without a parachute has a high mass and a low surface area, so they fall very fast.

Draw arrows for the upthrust and drag of an airplane.

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