Question

A car with an unknown intital velocity sees an obstacle and accelerates at -8 m/s for a period of 4 s until reaching a stop. what was the initial velocity of the car

Answer 1

Using the formula for acceleration, a = (v - u) / t, with the given acceleration of -8 m/s² and time of 4 s, the initial velocity (u) is calculated to be 32 m/s.

Step-by-step explanation:

To find out what was the initial velocity of the car, we can use the formula for acceleration which is a = (v - u) / t, where:

• a is the acceleration
• v is the final velocity
• u is the initial velocity
• t is the time

Since the car comes to a stop, the final velocity (v) is 0 m/s. The acceleration given is -8 m/s2 (negative because the car is slowing down), and the time (t) is 4 s. Plugging these values into the formula, we get:

-8 m/s2 = (0 m/s - u) / 4 s

Solving for u gives us the initial velocity:

u = 0 - (-8 m/s2 * 4 s)

u = 32 m/s

Therefore, the initial velocity of the car was 32 m/s.