Question

a sprinter starts from rest, and accelerates at 1.87m/s over a distance of 14.0m what is her final velocity?

Answer 1

7.24

Answer 2

\[a(t) = 1.87\]
\[v(t) = 1.87t\]
\[x(t) = \frac{1.87}{2}t^{2}\]
final velocity is at time when x(t) = 14
\[\frac{1.87}{2}t_f^{2} = 14\]
\[t_f = \sqrt{\frac{28}{1.87}}\]
\[v_f = 1.87*\sqrt{\frac{28}{1.87}}\]

Answer 3

yeah its about 7.236

Answer 4

a car slows down at -5.00 m/s2 until it comes to stop after traveling 15.0m how much time did it take to stop? HELP ME!!!!!! PLEASE (:

Answer 5

a jet fighter accelarates at 17.7 m/s2 increasing velocity from 119m/s to 233m/s. how much does that take?

Answer 6

both of these are found same way by defining acceleration , velocity, and distance functions
\[a(t) = -5\]
\[v(t) = -5t + v_o\]
\[x(t) = -2.5t^{2}+v_o t\]
car is stopped when velocity is 0
\[0 = -5t+v_o\]
\[v_o = 5t\]
car is stopped after 15m (x = 15)
\[15 = -2.5t^{2}+(5t)*t\]
solve for t
\[2.5t^{2} = 15\]
\[t = \sqrt{6}\]

Answer 7

2nd one, set up velocity function
\[v(t) = 17.7t + v_o\]
\[233 = 17.7t + 119\]
solve for t
\[t = \frac{233-119}{17.7}\]