Answer:
a) The kinetic energy of the ball at point A is 0.87 J.
b) The speed of the ball at point B is 5.0 m/s.
c) The work done on the ball is 6.7 J.
Explanation:
Hi there!
a) The equation of kinetic energy (KE) is the following:
KE = 1/2 · m · v²
Where:
m = mass.
v = speed.
At point A, the speed of the ball is 1.70 m/s and its mass is 0.60 kg. So the kinetic energy will be:
KE = 1/2 · 0.60 kg · (1.70 m/s)²
KE = 0.87 J
The kinetic energy at point A is 0.87 J.
b) In this case, we have the KE and have to find the speed of the ball:
KE = 1/2 · m · v²
2 · KE / m = v²
v = √(2 · KE / m)
v = √(2 · 7.6 J / 0.60 kg)
v = 5.0 m/s
The speed of the ball at point B is 5.0 m/s.
c) According to the work-energy theorem, the total work done on the ball is equal to the change in its kinetic energy:
W = ΔKE
W = final kinetic energy - initial kinetic energy
W = kinetic energy at B - kinetic energy at A
W = 7.6 J - 0.87 J
W = 6.7 J
The work done on the ball is 6.7 J
