Soal Fisika dan Penyelesaian

1.      Diket = t1=0S

t2=10S

∑F=0

            Ditanya: V……..?                                            → ∑F=0

            Jawab: Vt=V0+at                                      m.a=0

                        =70+0.10                                     a=0

                        =70 m/s

2.      Diket:   M=10 Kg

V0= 4 M/S

Vt=5M/S

X  =10M

            Ditanya            : F………..?

            Jawab  : Vt=V02+2aX                           → F=M.a

                        25=1t+20a                                    F=10.9/20

                        g=20a                                              9/2=4,5N

                        a=9/20

3.      Diket    : F1=20N

 F2=5N

M=10Kg

t=8s

            ditanya : X……?

            jawab   : ∑F     =F1-F2                          a=V/t

                                    =20-5=15N                  1,5=V/B

                        ∑F       =M.a                            V=12m/S2

                        15        =10a

                        A         =1,5 M/S2

                        X         =V.t

                                    =12.8

                                    =96M

4.      Diket    : V0     = 0

 Vt       =20M/S

t           =10S

S          =50N

            Ditanya            : M……….?

            Jawab  : Vt      =V0+at

                        20        =0+10a

                        a          =20/10

                                    =2M/S

                        M=F/a  =50/2     =25 Kg

5.      Diket    : M=150 Kg

ᶿ= 300

f= 10 M/S2

            Ditanya            : F……..?

            Jawab  : ∑Fx   = w sinᶿ

                                    =150.10√3

                                    =750√3

6.    

W sin θ

W cos θ

N

Diket    : m       = 80 kg
            θ          = 30°

Ditanya            :Gambarlah ..... ?
            N ..... ?

Jawab :
                      
     
                                  


                                  

Σfy      = N – W cos θ
                        = N      = W cos θ
                        = 800 . 1/2
                        = 400

7.      Diket    :m        = 4 kg
            g          = 10 m/s
            μk        = 0,2
            μs         = 0,4

Ditanya            : Besar gaya gesek       = .....  
            percepatan balok         = .....
            IF F₁ = 6 N, F₂ = 16 N & F₃ = 20 N

Jawab :          
            Σfy      = N – W
            W         = W
                         = 40

            fs max = μs . N                           fk = μk . 40
            = 0,4 . 40                                    = 0.2 .40
             = 16                                           = 8

            F₁         = 6 N, Jadi F₁ < fs
            F₁  < fs
                        a = 0 m/s          (Benda belum bergerak)
            F₂         =  16 N , Jadi F₂ = fs max
            a          = 0 m/s

            fk         = 8                                           f₃ > fk
            ΣF        = F – fk
                      
            4a        = 12/4
            a      = 3 m/s²

8.      Diket    : m       = 5 kg
            μs         = 0,4
            μk        = 0,2

 Ditanya:          fs ... ?
                        a ...  s ?

F = 30 N

Jawab :
                                    Σfy      = N – W
                                    N         = W
                                    W         = 50
                                    fs = μs . N                                fk = 0,2 . 50
                                        = 0,4 . 50                                 = 10
                                        = 20
                                    F = 30 N          = Σfx   = f – fk
                                                               as       = 30 – 10
                                                               a        = 20/5
                                                               a       = 4

9.       Centrifugal force is only a reaction to the existence of centripetal force objects moving in circle. It is only virtual force

  Example :
 Centrifugal force on a turning car


10.  Diket    :          R          = 60 m
                        Fs max             = 22500
                        m         = 1500 kg
Ditanya            :           V max ..... ?

 Jawab :           fs         = fs p
                                    22500  = 1500 . v²
                                                      60
                                    v²                     = 22500 . 60
                                                                1500
                                    v                      = √90
                                    v                      = 3 √10