Sorry the questions are...
A: how fast is the car going at the end of the breaking period
B: How far has the car gone from the start
A car starts from rest and travels for 5.5 s with a uniform acceleration of +1.7 m/s². The driver then applies the brakes, causing a uniform acceleration of -2.1 m/s² The brakes are applied for 1.90 s.
2 answers
braking, not breaking
since v=at, we have
(A) v = 1.7*5.5 - 2.1*1.90 = ____ m/s
(B) since s = vt + 1/2 at^2,
s = 1/2 * 1.7 * 5.5^2 + (1.7*5.5*1.90) - 1/2 * 2.1 * 1.90^2 = ____ m
since v=at, we have
(A) v = 1.7*5.5 - 2.1*1.90 = ____ m/s
(B) since s = vt + 1/2 at^2,
s = 1/2 * 1.7 * 5.5^2 + (1.7*5.5*1.90) - 1/2 * 2.1 * 1.90^2 = ____ m
1 answer