Question 1: Explain what a free body diagram is and its purpose in analysing forces acting on an object.

Answer: A free body diagram is a visual representation showing all the forces acting on an object, used to analyse the resultant force and motion.

Question 1: Identify three common forces that can act on an object resting on a surface.

Answer: Normal force, frictional force, gravitational force (weight).

Question 2: Describe the difference between balanced and unbalanced forces in the context of free body diagrams.

Answer: Balanced forces are equal in magnitude and opposite in direction, resulting in no change in motion; unbalanced forces are unequal, causing acceleration or deceleration.

Question 1: A box with a mass of 5 kg is pulled across a horizontal surface with a tension of 20 N. If the frictional force opposing the motion is 8 N, what is the net force acting on the box? Show your working.

Answer: Net force = Tension - Frictional force = 20 N - 8 N = 12 N.

Question 2: Calculate the acceleration of the box in the previous question. Use F = ma, where F is the net force, m is the mass, and a is acceleration.

Answer: a = F / m = 12 N / 5 kg = 2.4 m/s².

Question 1: Describe a simple experiment to investigate the effect of friction on the motion of an object. Include variables to control and safety precautions.

Answer: Use a flat surface and a block of known mass, attach a force gauge to pull the block at constant speed, vary the surface material to change friction, control pull speed, and ensure hands are clear of moving parts for safety.

Question 1: A cyclist is riding at constant velocity on a flat road. The cyclist's weight is 700 N. Identify all forces acting on the cyclist and explain why the cyclist maintains constant velocity using free body diagrams.

Answer: Forces acting include gravity (700 N downward), normal force from the ground (700 N upward), air resistance and rolling friction opposing motion. Since forces are balanced, net force is zero, so the cyclist maintains constant velocity.

Question 1: A 10 kg object is pulled with a force of 50 N on a horizontal surface. The object experiences a frictional force of 10 N. Draw the free body diagram and calculate the acceleration of the object.

Answer: For the free body diagram, forces include the 50 N pull, frictional force of 10 N opposing motion, gravity (100 N downward), and normal force (100 N upward). Acceleration = (50 N - 10 N) / 10 kg = 4 m/s².

Question 1: Explain how free body diagrams are used in designing safety features for vehicles, such as seat belts and airbags.

Answer: Free body diagrams help engineers analyse forces acting on occupants during collisions, enabling the design of safety features that mitigate impact forces and protect occupants.