Question

Please show all work and choose the correct answer.

As the starting gun sounds, racer A notices that his shoe is untied, so he takes 3 seconds to tie his shoe. He then accelerates at a constant 4m/s2 to catch his opponent and beat him by 5 meters. The other racer, B, had accelerated from the starting gun at 2 m/s2. Which of the following equations correctly expresses a kinematic equation for Racer A? 03=xa/ta OxA=2tA² OxA=4tA² 4=xa/ta OxA=1.5t4²

Answer 1

Solution:

Let the distance travelled by A is : X_A and time taken by A is : t_A

Since, initial velocity of A is 0 m/s. So, V_0A = 0 m/s

Now, According to the equation: X_A = V_0A t_A + (1/2)a_A t_A²

Since: a_A = 4 m/s²

Therefore: X_A = 2 t_A²