Question

Автомобил двигаясь от остановки под действием силы тяги 20кН, развил скорость 72км/ч. определить работу совершенную двигателем автомобиля если его ускорение 4м/с квадрат. пожалуйста помогите срочно надо

Answer 1

Находим время движения автомобиля
v=v0+a*t
20=0+4*t
t=5 c
определяем путь, пройденный автомобилем
S=at²/2
S=4*25/2=50 м
Определяем работу двигателя
A=F*S
A=20000*50 = 1000000 Дж
Работа равна миллиону Джоулей.

Answer 2

Дано:F тяги=20 кН V=72 км/ч а=4 м/с^2   Найти: А-?   Решение: А=F*l V=at 72км/ч=4*t t=корень из 72=18 l=a*t/2 l=(4*18)/2 l=36метров A=20кН*36метров=720кДж или 720*10^3 Дж ( если правильно перевел, но мог ошибиться)   Ответ: А=720кДж или 720*10^3Дж

Answer 3

Calculation of Work Done by the Car Engine

To calculate the work done by the car engine, we need to use the formula:

Work = Force x Distance

In this case, the force acting on the car is the tractive force, which is given as 20 kN (kilonewtons). The distance traveled by the car is not provided in the question. However, we can use the given information about the car's speed and acceleration to calculate the distance.

The car's speed is given as 72 km/h (kilometers per hour), and the acceleration is given as 4 m/s^2 (meters per second squared). To calculate the distance, we can use the following formula:

Distance = (Final Velocity^2 - Initial Velocity^2) / (2 x Acceleration)

Converting the speed from km/h to m/s:

72 km/h = 72 x (1000 m / 3600 s) = 20 m/s

Using the formula to calculate the distance:

Distance = (20^2 - 0^2) / (2 x 4) = 400 / 8 = 50 meters

Now that we have the distance, we can calculate the work done by the car engine:

Work = Force x Distance = 20 kN x 50 m = 1000 kNm

Therefore, the work done by the car engine is 1000 kNm.

Please note that the sources provided do not contain specific information related to this calculation. The calculation is based on the principles of physics and the given information in the question.