Question

A rifle is aimed horizontally at a target 100 ft away. The bullet hits the target .78in below the aiming point.
a) What is the bullet's time of flight?
b)What is its muzzle velocity?

The answers should be
a) 63 m/s
b) 1.6 X 10 exponent 3 ft/s

I don't know how to get to these answers-how to solve it.

Answer 1

Before you can get far in kinematics you must understands and memorize these 5 formulas.
http://plaza.obu.edu/corneliusk/ps/phys/kelm.pdf

Answer 2

I have been trying to solve it by .5gt to the power of 2, but I keep getting the wrong answers. I also converted 100 ft to meters and .75 (not .78) in. to meters.

Answer 3

I use the equation number 5?

Answer 4

For t I got 8.18 s
and for velocity I got 40.07
which is wrong.....

Answer 5

That seems like waaaay to too much time. The time is the time for the bullet to drop .78 in due to gravity. Find out that time due to acceleration due to gravity 32 ft per second,per second.

Answer 6

After getting the correct time, use the distance of 100 ft and calculate velocity.

Answer 7

I note you are aware of the conversion of units. Good luck with this.