An object moves with initial speed 4 m/s and constant acceleration 2 m/s^2. How far does it travel in 5 s?
Answer and explanation
Correct answer: B. 45 m
- Step 1: Use s = v0 t + (1/2) a t^2.
- Step 2: s = 4 x 5 + 0.5 x 2 x 5^2 = 45 m.
Answer
45 m.
Why not the others: Forgetting the factor 1/2, using the final speed for the whole time, or leaving the time unsquared produces the other distances.
Practise more Mechanics.
Free questions with an explanation for every one, and full timed Državna Matura (Montenegro) mock tests.
More Mechanics questions
- A car starts at 10 m/s and accelerates uniformly at 5 m/s^2 for 6 s. What is its final speed?
- A 10 kg block is pulled along a rough floor by a horizontal force of 30 N. Friction is 10 N. What is the block's acceleration?
- A frictionless slide is 3.2 m high. A child starts from rest at the top. Taking g = 10 m/s^2, what is the child's speed at the bottom?
- A 2 kg cart moving at 6 m/s hits a 1 kg cart at rest and the two stick together. What is their common speed afterwards?
- A car drives around a circular curve of radius 5 m at 10 m/s. What is its centripetal acceleration?
- What is the gauge pressure due to water at a depth of 2 m? (density 1000 kg/m^3, g = 10 m/s^2)