An object experiences an acceleration of 8.5 m/s^2 over a distance of 300 m. After that acceleration it has a velocity of 400 m/s. What was its velocity before being accelerated? *

393.6m/s

Explanation:

Given parameters:

Acceleration  = 8.5m/s²

Distance  = 300m

Final velocity  = 400m/s

Unknown:

Initial velocity  = ?

Solution:

To solve this problem, we use the expression below;

             v² = u²  + 2as

v is the final velocity

u is the initial velocity

a is the acceleration

s is the distance

      So;

               v²  - 2as = u²

        u²   = v²   - 2as

        u²  = 400²   - (2 x 8.5 x 300)  

         u   = 393.6m/s

b. false

explanation:

suppose a rock in free fall is dropped off a cliff. after falling for 5 seconds, its speed would not be 100 m/s.

the answer is c. the lower legs are levers, and the knees are fulcrums. the ankles hold the loads.