When you exert a force on the coin, it will accelerate. If you push the coin and it moves at a constant velocity, the friction force must be equal to the force that you are exerting. This is an example of a balanced force. When the net force is greater than 0 N, the is an unbalanced force.
Answer: 7.41 m/s
Explanation: By using the law of of energy, kinetic energy of the brick as it falls equals the potential energy before falling.
Kinetic energy = mv²/2, potential energy = mgh
mv²/2 = mgh
v²/2 = gh
v² = 2gh
v = √2gh
Where g = 9.8 m/s², h = 2.80m
v = √2×9.8×2.8 = 7.41 m/s
Answer:
60 km/h
Explanation:
Simplify the speed:
120÷2=60
Hence, the average speed is 60 km/h.