Question How do the velocity and acceleration of a projectil

Question: How do the velocity and acceleration of a projectile change Pre-Laboratory Work: Part P-1: over time? Photogate Air Track 1. In this laboratory you will be pushing a cart though a photogate. A photogate operates by sending out an electromagnetic signal (light) from one side of the gate and detecting it or the other side. If the signal is blocked by something, the gate measures how long it is blocked. How could this be used to measure the speed of a cart? Explain your answer a. b. Would you know the velocity of the cart from this measurement? Explain your answer. c. If the answer is no, how will you keep track of the direction as you perform this experiment? (You must show that you have read the experiment in this answer.) Explain your answer. Last revised 7/17/2015 Collisions-8.1

Solution

1) a)

If we know the length of the cart of the cart ( let it be L)

we can measure how long the signal is blocked by the cart ( let it be t)

that will give us the time that the cart takes to cover a distance that is equal to its own length

so speed = L/ t

b)

we cannot measure the velocity because in the above method we cannot determine the direction in which the cart is moving.

c)

we can track the direction by using two photogates side by side.

suppose the signal of the left photogate gets blocked earlier than the right photogate we can tell that cart moves from left to right.