Thermal Physics Exam Trivia Quiz!

Explanation
Average speed equal to total distance multiply by the total time taken.

As 1 min= 60 s and 1 km = 1000 m

Hence, Average speed

= 60 km / 20 mins

=( 60 km x 1000 m/km) / (20 min x 60 s/min)

= 60000 m/ 1200 s = 50 m/s

Explanation
From the speed-time graph, we can obtain

a) Instantaneous speed from the Y-axis of the graph
b) Distance travel from the area under the graph
c) Instantaneous acceleration from the gradient of the graph

At time t, both graphs intercept with one another, and hence both of them run at the same speed(Since they have the same Y value). Both of the runners experience acceleration as the speed of both graphs increases with time. However, runner one experiences constant acceleration while runner two experiences various acceleration. Runner one will only overtake runner two after time t, not at time t.

Explanation
A free-falling object will experience a free-fall acceleration of 9.8m/s.

Gravitational will always the same in free-fall conditions and hence the acceleration should be constant. (ideal assumption)

Meanwhile, as the stone experiences acceleration, it means that the speed of the stone increases with time.

Explanation
From the distance-time graph, we can obtain

a) instantaneous distance traveled from the Y-axis of the graph
b) instantaneous speed from the gradient of the graph
c) average speed by dividing final Y-axis value with total time taken

As the objects experience a constant speed for some time, the graph should be increased with time at a constant gradient.
After a few seconds, The graph will curve up due to it begins to experience an acceleration.

Explanation
From the speed-time graph, we can obtain

a) instantaneous speed from Y-axis
b) Instantaneous acceleration from the gradient at a certain time
c) total distance traveled from the area under the graph

When an object traveled under acceleration, its speed-time graph should have a positive gradient. And hence X region is the total distance traveled under acceleration

Explanation
From the distance-time graph, we can obtain

a) instantaneous distance traveled from Y-axis
b) Instantaneous speed from the gradient at a certain time
c) Average speed by dividing the Y-axis value with the total time taken

From the speed-time graph, we can obtain
a) instantaneous speed traveled from Y-axis
b) Instantaneous acceleration from gradient at a certain time
c) Total distance traveled from the area under the graph

When an object remains stationary, its velocity =0 m/s and its distance will independent with time

Explanation
Average speed = Total distance travelled / Total time taken

Thus,
Average speed = 100 km/ 2hr
Average speed = 50 km/hr

and hence it is regardless of the maximum and minimum speed during the journey

Explanation
Average speed

= total distance / total time
=(10 +5 + 5 +10)km / (30 min x 1 hr/60min)
= (30km)/0.5hr
= 60km/hrs