Answer:
62.64 RPM.
Explanation:
Given that
m= 4.6 g
r= 19 cm
μs = 0.820
μk = 0.440.
The angular speed of the turntable = ω rad/s
Condition just before the slipping starts
The maximum value of the static friction force =Centripetal force


Therefore the speed in RPM will be 62.64 RPM.
The horizontal force : f = k*N
k- coefficient of friction
k = f /N
N = m * g = 45 kg * 9.81 m/s² = 441.45 N
k = 25 N : 441.45 N = 0.057
Answer C) 0.057
The amount of heat needed to increase the temperature of a substance by

is given by

where
m is the mass of the substance

the specific heat capacity

the increase in temperature
In our problem, the mass of the water is m=750 g, the specific heat is

and the amount of heat supplied is

, so if we re-arrange the previous formula we find the increase in temperature of the water:
Answer:
83,900 J
Explanation:
First, find the acceleration:
F = ma
1150 N = (1600 kg) a
a = 0.719 m/s²
Now find the final velocity.
Given:
Δx = 45.8 m
v₀ = 6.25 m/s
a = 0.719 m/s²
Find: v
v² = v₀² + 2aΔx
v² = (6.25 m/s)² + 2 (0.719 m/s²) (45.8 m)
v = 10.2 m/s
Now find the final KE:
KE = ½ mv²
KE = ½ (1600 kg) (10.2 m/s)²
KE = 83,920 J
Rounded to three significant figures, the final kinetic energy is 83,900 J.