Ahockey puck is hit on a frozen lake and starts moving with a speed of 13 m/s. seven seconds later, its speed is 6.7 m/s. what is its average acceleration? the acceleration of gravity is 9.8 m/s 2 . answer in units of m/s 2 .

-0.9 m/s²

Explanation:

t = Time taken by the hockey puck = 7 seconds

u = Initial velocity of the hockey puck = 13 m/s

v = Final velocity of the hockey puck = 6.7 m/s

a = Acceleration of the hockey puck

Equation of motion

The acceleration of the hockey puck in the seven seconds is -0.9 m/s²

The acceleration due to gravity is not needed to find the acceleration of the puck.

answer would be letter choice (a),   a ball resting on a shelf. would be another example of potential energy   >   stored energy > not moving.

a ball spinning on a finger   >   kinetic energy > moving energy

a ball rolling on the ground   >   kinetic energy   > moving energy

a   ball flying through the air   > kinetic energy   >   moving energy

hope that                                         : )