A racing car travelling with constant acceleration increases its speed from 10 m/s to 50 m/s over a distance of 60 m. How long does this take?
Correct answer: A. 2.0 s
- A. 2.0 s
- B. 5.0 s
- C. 4.0 s
- D. 8.0 s
Explanation
The scenario describes a uniformly accelerated motion, starting with an initial velocity (u) of 10 m/s and reaching a final velocity (v) of 50 m/s over a distance (s) of 60 m. To find the time taken, we first determine the acceleration using the formula:v2 = u2 + 2as.Rearranging for a, we have: a = (v2 - u2) / (2s) = (502 - 102) / (2 x 60) = 20 m/s2.Next, we use the equation v = u + at to find the time t: t = (v - u) / a = (50 - 10) / 20 = 2 seconds.Therefore, the correct time taken is 2 seconds. Options B, C, and D result from incorrect application of the equations, leading to inaccurate calculations.
Last updated
About Force and Motion
Displacement, velocity and acceleration describe motion, including the horizontal and vertical components of projectile motion. The chapter connects these quantities with Newton's laws, momentum and impulse, then applies conservation of momentum to collisions, distinguishing elastic collisions from inelastic ones.
Practise Force and Motion
1,416 free Force and Motion MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
(1, 1, 1) . (2, 2, 2)
1st law of motion gives the definition of:
2nd law of motion measures which quantity?
7.0 kg bowling ball experience a net force of 5.0N. What will be its acceleration?
A 0.2 kg rubber ball is dropped from the window of a building. It strikes the sidewalk below at 30m/s and rebounds up at 20m/s. The impulse on the ball during the collision is: