2. The stage choreography for a play requires an actor to walk 5 steps forward, 9 steps left, and
2 steps backward to be standing over the trap
door. What are the components of the actor's
motion from the starting position?
O a. 7 steps left and 2 steps forward
Ob.7 steps left and 2 steps backward
O c. 9 steps left and 3 steps backward
d. 9 steps left and 3 steps forward

D

Explanation:

Given that the actor walk 5 steps forward, 9 steps left, and 2 steps backward to be standing over the trap

door.

Let first consider the steps forward and the steps backwards

The displacement = 5 - 2 = 3

That is, 3 steps forward.

Therefore,

The components of the actor's

motion from the starting position will be:

9 steps left and 3 steps forward

D is the correct answer.

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

this would be about 43%