A cars brakes operate using hydraulics. A small piston is connected to the brake pedal with an area of 0.2 m^2. This is connected to the brake pads, where the piston has an area of 0.9 m^2. If it requires 800 N of force to slow down the car, how hard do you have to push on the pedal? MUST SHOW ALL WORK ( work, + answer + sentence of ( example: it would require 2N to push on the pedel )

the velocity you are looking for is made up of two parts: horizontally velocity, vh, and its vertical velocity, vv. the actual velocity of the ball will be these two parts added together, and because velocity is a vector then they will need to be added vectorially.  

neglecting air resistance etc etc.,  

the horizontal velocity component will be constant (because there is no accelerating force in the horizontal direction.  

vh = 8 ms-1  

the vertical velocity component has an accelerating force: 'g'.  

using v = u +at where a = g = 9.81 ms-2.  

the vertical component of velocity, vv = 0 + gt = vv =9.81 x 2  

vv = 19.62 ms-1 . the zero appears because the virtical component of velocity at time t=0 is zero. remember, the ball was thrown horizontally.  

how fast it will be moving (it actual path (being a parabola )) will be the vector sum of these two.  

adding vectorally gives: -  

v = sqr root (8^2 + 19.62^2) = sqr root(64+384.9) = 21.18 or 21.2 ms-1

magnified images possible images can be real = projected onto a screen

d. air pressure decreases as altitude increases.

which three statements are true about all alloys?