Question

С какой силой надо затормозить автомобиль весом G=2кН , движущийся по горизонтальному пути ,что бы в течении 30 с его скорость уменьшилась с 60км\ч до 20км\ч. С полным решением плиз очень надо именно правильное решение.

Answer 1

ДАНО

t=30c

v1=60 км/ч=50/3 м/с

v2=20 км/ч=50/9 м/с

G=2кН =2000 Н

g=10  м/с2

НАЙТИ

F - ?

РЕШЕНИЕ

ускорение a = v2-v1  /  t = (50/9 -50/3) / 30 = -10/27 м/с2

масса авт-ля  m = 2000 /10 =200 кг

сила торможения  F = ma = 200*(-10/27) = - 74 Н

ОТВЕТ 74 Н

Answer 2

Calculating the Force Required to Decelerate the Car

To calculate the force required to decelerate the car, we can use the equation of motion:

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

Given: - Initial velocity (u) = 60 km/h = 16.67 m/s - Final velocity (v) = 20 km/h = 5.56 m/s - Time (t) = 30 s

We can calculate the acceleration using the equation: Acceleration (a) = (v - u) / t

Substitute the given values: Acceleration (a) = (5.56 - 16.67) / 30

Let's calculate the acceleration: Acceleration (a) = -0.376 m/s^2

The negative sign indicates deceleration.

Calculating the Force

Now, we can calculate the force required to decelerate the car using the equation: Force (F) = Mass (m) * Acceleration (a)

Given: - Mass (m) = 2 kN = 2000 N

Substitute the given values: Force (F) = 2000 * (-0.376)

Let's calculate the force: Force (F) = -752 N

The negative sign indicates that the force is acting in the opposite direction of the car's motion, which is the direction of deceleration.

Therefore, the force required to decelerate the car is 752 N in the direction opposite to its motion.