Question

За скільки секунд автомобіль, рушаючи з місця, набере швидкості 72 км/год, якщо його прискорення рівне 2 м/с2?​

Answer 1

Відповідь:

10с

Пояснення:

Vo=0

Vm=20m/c  (72km/h)      

a=2m/c²      t=Vm/a=20/2=10

Answer 2

Calculating the Time to Reach 72 km/h from Rest

To calculate the time it takes for the car to reach a speed of 72 km/h from rest, we can use the following formula:

Final velocity (v) = Initial velocity (u) + Acceleration (a) * Time (t)

Given: - Initial velocity (u) = 0 (as the car is starting from rest) - Final velocity (v) = 72 km/h - Acceleration (a) = 2 m/s^2

First, we need to convert the final velocity from km/h to m/s, as the acceleration is given in m/s^2.

Conversion of Final Velocity from km/h to m/s

To convert 72 km/h to m/s, we use the conversion factor: 1 km/h = 0.277778 m/s.

So, 72 km/h = 72 * 0.277778 m/s = 20 m/s.

Now, we can use the formula to calculate the time it takes for the car to reach this speed.

Calculation

Using the formula v = u + at, where: - v = final velocity = 20 m/s - u = initial velocity = 0 m/s - a = acceleration = 2 m/s^2 - t = time (in seconds, which is what we need to find)

We rearrange the formula to solve for time (t): t = (v - u) / a

Substituting the given values: t = (20 - 0) / 2 = 10 seconds

So, the car will take 10 seconds to reach a speed of 72 km/h from rest with an acceleration of 2 m/s^2.

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