Question

Машина равномерно движется со скоростью 72 км/ч. Какую работу совершит она за 10с, если сила тяги её мотора 2 тыс. Н?

Answer 1

v=72/3.6=20 м/с   t=10 c   F=2000 H   A=?

A=F*s      s=v*t     A=F*v*t=2000*20*10=4*10^5 Дж  (400 кДж)

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Answer 2

Calculating the Work Done by a Car

To calculate the work done by the car, we can use the formula:

Work = Force × Distance

Given: - The car is moving at a constant speed of 72 km/h. - The force of its motor is 2000 N. - The time duration is 10 seconds.

First, we need to convert the speed from km/h to m/s, as the standard unit of force is Newton (N) and the standard unit of distance is meter (m).

Converting Speed from km/h to m/s

To convert the speed from km/h to m/s, we use the formula: Speed (m/s) = (Speed in km/h) × (1000 m/1 km) × (1 h/3600 s)

Converting the given speed: 72 km/h = 72 × 1000 m/3600 s = 20 m/s.

Calculating the Distance Traveled

The distance traveled by the car in 10 seconds at a constant speed of 20 m/s can be calculated using the formula: Distance = Speed × Time

Distance = 20 m/s × 10 s = 200 meters.

Calculating the Work Done

Now, we can calculate the work done by the car using the formula: Work = Force × Distance

Work = 2000 N × 200 m = 400,000 joules (J).

Therefore, the car will perform 400,000 joules of work in 10 seconds with a motor force of 2000 N.