Using the constant acceleration formula v^2 = u^2 + 2as, we can figure out that it would take a distance of 193.21m to reach 27.8m/s
What does thrice mean not being mean or anything just saying so I can help with the question
The answer is C hope this helps <span />
Since there is no friction between the ladder and the wall, there can be no vertical force component. That's the tricky part ;)
So to find the weight, divide the 100N <em>normal</em> force by earths gravitational acceleration, 9.8m/s^2

Then;
Draw an arrow at the base of the ladder pointing towards the wall with a value of 30N, to show the frictional force.
She knows the speed limit in the area, and also saw the speed you were going on the speedometer. The speed you were going was faster than the limit allowed, so that's how she knew you were going too fast.