- #1

- 96

- 0

1) A projectile is fired an angle x at a speed v_o. The point it is fired from also happens to be the start of an incline which is at an angle y (x>y). Determine the distance up the incline where the projectile lands.

How do I approach this problem? I have no idea how to start.

2) A baseball is thrown straight up into the air. It passes point A with the speed v and point B at a distance d higher with the speed of v/2. How much higher will the ball rise before falling? ( Hint: you don't need to do any calculations)

I know that v = v_o -9.8t. Therefore, v is decreasing at a constant rate. If it takes t seconds to decrease by 1/2, then it will also take the same t second to reach zero. However, how do I express this as a distance.

3) A rock is dropped off of a high cliff. The sound of it striking the ocean is heard a time T later. Assume the speed of sound is V_sound. Determine the height of the cliff.

I know that T = t_1 + t_2 where t_1 is the time it takes the rock to hit the ocean while t_2 is the time sound travels.

The fall is 0 = H + 1/2 v_o * t - 1/2 gt^2

t= SQRT(2H/g)

H = V_sound (T - SQRT (2H/g))

How do I find H from here?

4) A projectile is fired with speed V_o at angle x. Find the maximum value of x such that the projectile's distance from the origin is always increasing up until the time when it hits the ground.

I know that the maximum range is at 45 degree, but how do I find this? The maximum value includes both the horizontal and vertical values of displacement.

I know I asking a lot of questions, but I really need to know these concepts for a test coming up. Please get me started on some of these problems. Any help will be greatly appreciated. Thanks in advance.