Предмет: Физика, автор: kenanjafarli077

под действием силы 4 Ньютонов тело за 5 секунд приобрело кинетическую энергию равную 40 дж. Чему равна масса тела ? Начальняя скорость равна 0​

Ответы

Автор ответа: zinovicgrigorij
0

Ответ: 5кг

Объяснение:

Дано:

F=4Н

t=5c

Ек=40Дж

-------------

m-?

F=ma

m=F/a

Ек=mV²/2

m=2Ек/V²

F/a=2Ек/V²

V=at=5a

4/а=2*40/(25а²)

4/а=16/5а²

16а=20а²

20а=16

а=0,8м/с²

m=4/0,8=5кг

Автор ответа: fatt52
1

Ответ:

5 кг

Объяснение:

F=4 H   Δt=5 c   E=40 Дж    m=?

===

E=m*v²/2 ---> Δv=√(2*E/m)

m*Δv=F*Δt

√(2*E*m)=F*Δt

m=(F*Δt)²/(2*E)=(4*5)²/(2*40)=5 кг

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