Answer:
541.89 Watt
Explanation:
Consider the motion of rock on rough surface
μ = Coefficient of kinetic friction = 0.63
acceleration caused to kinetic friction is given as
a = - μg
a = - (0.63) (9.8)
a = - 6.2 m/s²
vâ‚€ = initial velocity of the rock = 9.25 m/s
t = time taken to stop
v = final velocity = 0 m/s
Using the equation
v = vâ‚€ + a t
0 = 9.25 + (- 6.2) t
t = 1.5 sec
m = mass of the rock = 19 kg
Energy lost due to friction is given as
E = (0.5) m (v₀² - v²)
E = (0.5) (19) (9.25² - 0²)
E = 812.84 J
Average thermal power is given as
[tex]P = \frac{E}{t}[/tex]
[tex]P = \frac{812.84}{1.5}[/tex]
P = 541.89 Watt
