I can solve that the problem about motion in one dimention

[bl4cksta]

A motorcyclist heading east accelerates with a constant acceleration
of 4.0 m/s2. At time t = 0 he is 5.0 m east of a signpost, moving east
at 15 m/s.
a) Find his position and velocity at time t = 2.0 s.
b) Where is the motorcyclist when his velocity is 25 m/s?

how can i solve this ??

 

[tiny-tim]

welcome to pf!

hi bl4cksta! welcome to pf!

you have v_i a and t, and you want v_f and s

use the standard https://www.physicsforums.com/library.php?do=view_item&itemid=204" equations …

what do you get? ​

 

[bl4cksta]

thank you. is it? a=Vf-Vi/ΔT is it my formula? or V=V0+at2

 

[tiny-tim]

hi bl4cksta!

(try using the X² and X₂ icons just above the Reply box )

a=Vf-Vi/ΔT is it my formula?

yes, that'll give you v_f …

you're using it because it has v_i a t and v_f

or V=V0+at2

where did you get that from??

see the pf library for the standard https://www.physicsforums.com/library.php?do=view_item&itemid=204" equations

… to find s, you need one with v_i a t and s

… what do you get? ​

 

[bl4cksta]

hi bl4cksta!

(try using the X² and X₂ icons just above the Reply box )


yes, that'll give you v_f …

you're using it because it has v_i a t and v_f


where did you get that from??

see the pf library for the standard https://www.physicsforums.com/library.php?do=view_item&itemid=204" equations

… to find s, you need one with v_i a t and s

… what do you get? ​

oops I am sorry i give you a wrong formulas

 

[bl4cksta]

hi bl4cksta!

(try using the X² and X₂ icons just above the Reply box )


yes, that'll give you v_f …

you're using it because it has v_i a t and v_f


where did you get that from??

see the pf library for the standard https://www.physicsforums.com/library.php?do=view_item&itemid=204" equations

… to find s, you need one with v_i a t and s

… what do you get? ​

oops I am sorry i give you a wrong formula