Question

100N is applied over 10 m on a mass of 5kg. The velocity is now 20 m/s. What was the initial velocity.

Answer 1

F= 100N
d = 10 m
m= 5 kg
Vf= 20 m/s
Vi =?

F= ma using this formula solve for the acceleration

Then, apply one of the 5 kinematics equation: \(\sf V_f^2=V_i^2+2ad\) to solve for \(\sf V_i\)


btw, this is the math section (:

Answer 2

100/5=a so acceleration=20 and yes sorry s: i posted wrong section

Answer 3

20^2=V^2i+2(20)(10)

Answer 4

don't worry it's okay (:

and yes, acceleration value is right

yes evaluate that to get \(\sf V_i\)

Answer 5

40/400=V^2i

Answer 6

400/400*

Answer 7

\(\sf 20^2=V^2i+2(20)(10) \\ 20^2-2(20)(10) =V_i^2\\V_i= \sqrt{20^2-2(20)(10)}\)

Answer 8

so you would subtract 2(20)(10) on both sides to make it negative then sqrt to get just Vi?

Answer 9

and the velocity would be 0m/s

Answer 10

yes, don't divide because the operation between \(\sf V_i^2\) and \(\sf 2ad\) is addition not ,multiplication

Answer 11

yes :) that would be the initial velocity

Answer 12

Thank you :D