Question

как это решается :1)Кран поднимает груз массой 4т со скоростью 0.1м/с. N=? (N=4000Вт).2)какую работу может совершить пуля массой 9г со скоростью 100м/с.(А=45Дж).Плииииз пожалуйста помогите !

Answer 1

1)Кран поднимает груз массой 4т со скоростью 0.1м/с. N=? (N=4000Вт).

 

мощность N=F*v =mg*v=4000*10*0.1=4000 Вт

 

2)какую работу может совершить пуля массой 9г со скоростью 100м/с.(А=45Дж).

 

A= Ek=mv^2/2 =0.009*100^2/2 =45 Дж

Answer 2

Calculation of Power (N) for a Crane lifting a 4-ton load at a speed of 0.1 m/s

To calculate the power (N) required for a crane to lift a 4-ton (4000 kg) load at a speed of 0.1 m/s, we can use the formula:

Power (N) = Force (F) x Velocity (v)

The force required to lift the load can be calculated using the formula:

Force (F) = Mass (m) x Acceleration due to gravity (g)

Given that the mass of the load is 4 tons (4000 kg) and the acceleration due to gravity is approximately 9.8 m/s², we can calculate the force:

Force (F) = 4000 kg x 9.8 m/s²

Now, we can substitute the force and velocity values into the power formula:

Power (N) = (4000 kg x 9.8 m/s²) x 0.1 m/s

Calculating this expression will give us the power required by the crane to lift the load.

Let's perform the calculations:

Force (F) = 4000 kg x 9.8 m/s² = 39200 N

Power (N) = (39200 N) x (0.1 m/s) = 3920 W = 3920 J/s

Therefore, the power (N) required for the crane to lift a 4-ton load at a speed of 0.1 m/s is 3920 watts (W) or 3920 joules per second (J/s) [[1]].

Calculation of Work (A) for a Bullet with a mass of 9 g and a velocity of 100 m/s

To calculate the work (A) that can be done by a bullet with a mass of 9 g (0.009 kg) and a velocity of 100 m/s, we can use the formula:

Work (A) = 0.5 x Mass (m) x Velocity (v)²

Given that the mass of the bullet is 9 g (0.009 kg) and the velocity is 100 m/s, we can substitute these values into the work formula:

Work (A) = 0.5 x 0.009 kg x (100 m/s)²

Let's perform the calculations:

Work (A) = 0.5 x 0.009 kg x (100 m/s)² = 0.5 x 0.009 kg x 10000 m²/s² = 45 J

Therefore, the work (A) that can be done by a bullet with a mass of 9 g and a velocity of 100 m/s is 45 joules (J) [[2]].

I hope this helps! Let me know if you have any further questions.