Understanding Force 2

In which situation is no resultant force needed?

The diagrams show four identical objects. Each object is acted on by only the three forces shown. Which object accelerates to the right, with the smallest acceleration?

A car travels along a straight road. The speed-time graph for this journey is shown. During which labelled part of the journey is the resultant force on the car zero?

The engine of a car produces a driving force of \(5000 \mathrm{~N}\) on the car. Resistive forces \(R\) also act on the car, as shown.

The car has a mass of \(800 \mathrm{~kg}\) and an acceleration of \(1.0 \mathrm{~m} / \mathrm{s}^2\).
What is the value of \(R\) ?

A car travels forwards along a straight horizontal road. Only the horizontal forces acting on it are shown.

The length of each arrow represents the size of each force. How do these forces affect the motion of the car?

An object decelerates from \(25.0 \mathrm{~m} / \mathrm{s}\) to \(5.0 \mathrm{~m} / \mathrm{s}\) in a time of \(4.0 \mathrm{~s}\). It has a mass of \(50 \mathrm{~kg}\). What is the resultant force on the object?

A mass of \(20 \mathrm{~kg}\) is held stationary by a rope passing over a frictionless pulley.

What is the tension \(T\) in the rope?

Which statement correctly describes the effects of placing a heavy load in a car?

When a molecule rebounds from a wall, a force is exerted on the wall.
What causes this force?

Four objects are each acted on by only two forces, as shown.
Which object is in equilibrium?