Skip to main content
GIOPHYSICS
Menu

IB · A · multiple choice

Space, time and motion · Question 3

Space, time and motion · Original GioPhysics question with a detailed, mark-by-mark answer guide.

Demand
routine
Marks
1
Topics
1
Answer
Complete
Force–time graph for the resultant force on the object00.050.100.150.20010203040time t / sforce F / N
Figure 1A graph of force F / N against time t / s on gridded axes, the force axis marked 0 to 40 N and the time axis 0 to 0.20 s. The plotted line rises straight from the origin to 40 N at t = 0.10 s and falls straight back to zero at t = 0.20 s, so the trace is a triangle standing on the time axis.
multiple choice1 mark

A resultant force acts on a stationary object of mass 0.50 kg. The force–time graph is a triangle rising from zero at t = 0 to a peak of 40 N at t = 0.10 s and falling back to zero at t = 0.20 s. What is the speed of the object at t = 0.20 s?

  1. A

    4.0 m s⁻¹

  2. B

    8.0 m s⁻¹

  3. C

    16 m s⁻¹

  4. D

    20 m s⁻¹

Ready to self-mark?Reveal the detailed answer guide
Answer overviewCorrect answer: B — 8.0 m s⁻¹
01

Answer and reasoning

1 mark
How to approach it

Predict from the governing principle before looking for a matching option. Then reject alternatives by checking direction, units, limiting behaviour or the physical meaning of each statement.

  1. 1

    The correct choice is B: 8.0 m s⁻¹

  2. 2

    The impulse is the area under the graph, ½ × 0.20 × 40 = 4.0 N s, and dividing by the mass gives 8.0 m s⁻¹. C treats the graph as a rectangle of height 40 N; A stops at the impulse and forgets to divide by the mass.

Private on this device

Did your answer earn the marks?

Compare the reasoning point by point, then choose what happens next.