Density is mass over volume: d=m/v
d = 393/50 => d = 7.86 g/ml
Answer:
0.68 seconds
Explanation:
Data provided in the question:
Mass of the box = 50 kg
Speed of the box = 1.0 m/s
Coefficient of friction, μ = 0.15
Now,
Force applied = μmg
Here,
g is the acceleration due to gravity = 9.8 m/s²
Thus,
F = 0.15 × 50 × 9.8
= 73.5 N
Also,
Force = Mass × Acceleration
thus,
73.5 N = 50 × a
or
a = 1.47 m/s²
After doubling the speed
Final speed = 2 × Initial speed
= 2 × 1 m/s
= 2 m/s
Also,
Acceleration = [change in speed] ÷ Time
or
1.47 = [ 2 - 1 ] ÷ Time
or
Time = 1 ÷ 1.47
or
Time = 0.68 seconds
At E the potential energy is maximum/highest. The potential energy decreases as it goes down and increases as it goes up. so if the pendulum swinged from E to A, potential energy would decrease till C and increase till A.
