1. Remember that : and the unit is and not m.
3. a) Right
b) ... what can I say here... you used the rounded value you got previously, and this is often a very risky thing to do... The safest way is to use what you were given and what you are sure. For instance, the internal angle in a triangle is 180 degrees.
The ladder, the ground and the wall make up the three sides of a right angle triangle (sketches always help). Hence, the angle the wall makes with the ladder becomes (180 - 90 - 65) = 25 degrees exactly, and not 25.8 degrees.
a) No, that's not it. The displacement is given by the area under the graph. Can you try this again?
c) Um... the gradient at a point gives the acceleration, right? What is the gradient at t = 4s?
5. Right... the question is asking you for the distance required for stopping completely.
I'll advise you to find the acceleration if you cannot 'play' with variables without making mistakes.
Use the equation:
For the car to stop, we get v = 0. We know that u = 15.6, s = 12.2.
You can find a.
Then, use the same equation to get the distance for the higher speed.
This time, you know a, you are given vo and you have to find s, knowing tha v = 0
Post what you get!