the football player has speed
Answer:
680 J
Explanation:
Mechanical energy = potential energy + kinetic energy
ME = PE + KE
ME = mgh + ½ mv²
ME = (77.1 kg) (9.8 m/s²) (0.90 m) + ½ (77.1 kg) (0 m/s)²
ME = 680 J
Answer:
According to your question although I think an object undergoing uniform circular motion is moving with a constant speed. Nevertheless, it is accelerating due to its change in direction. The direction of the acceleration is inwards,therefore a force perpendicular to an objects velocity change the direction of the velocity but not its magnitude.
What is the question asking?
Explanation:
A worker picks up the bag of gravel. We need to find the speed of the bucket after it has descended 2.30 m from rest. It is case of conservation of energy. So,

h = 2.3 m

So, the speed of the bucket after it has descended 2.30 m from rest is 6.71 m/s.