A paper airplane is thrown horizontally with a velocity of 20 m/s. The plane is in the air for 7.43 sec before coming to a standstill on the ground. What is the acceleration of the plane? Please try and add the process to doing this problem because I don't know the formula to get this

Acentrifuge in a medical laboratory rotates at an angular speed of 3,700 rev/min. when switched off, it rotates through 54.0 revolutions before coming to rest. find the constant angular acceleration (in rad/s2) of the centrifuge. your response is within 10% of the correct value. this may be due to roundoff error, or you could have a mistake in your calculation. carry out all intermediate results to at least four-digit accuracy to minimize roundoff error. rad/s2