Answer:
√2µgd = vi
Explanation:
Given that the mass of object is m
Sliding speed of object is vi
coefficient of kinetic friction is µ
Distance covered is d
Final speed, vf is 0
Equation to apply will be;
v²f=v²i-2µgd where g is acceleration due to gravity
v²f+2µgd=v²i----------------------but v²f = 0
2µgd=v²i
√2µgd = vi
Answer:
25 m/s in the opposite direction with the ship recoil velocity.
Explanation:
Assume the ship recoil velocity and velocity of the cannon ball aligns. By the law of momentum conservation, the momentum is conserved before and after the shooting. Before the shooting, the total momentum is 0 due to system is at rest. Therefore, the total momentum after the shooting must also be 0:

where
are masses of the ship and ball respectively.
are the velocities of the ship and ball respectively, after the shooting.



So the cannon ball has a velocity of 25 m/s in the opposite direction with the ship recoil velocity.
Answer:
a) 0.723 m²
b) 2000V
Explanation:
Given that
Thickness of the capacitor, d = 0.08*10^-3 m
Dielectric constant of the capacitor, k = 2.5
Dielectric strength of the capacitor, E = 50*10^6
Capacitance of the capacitor, C = 0.2*10^-6
Permittivity of free space, E• = 8.85*10^-12
a)
The area, A is given by the formula
A = (C * d) / (k * E•)
A = (0.2*10^-6 * 0.08*10^-3) / (2.5 * 8.85*10^-12)
A = 1.6*10^-11 / 2.213*10^-11
A = 0.723 m²
b)
Potencial difference, V is given by the formula
V = E * d
V = 1/2 * 50*10^6 * 0.08*10^-3
V = 1/2 * 4000
V = 2000 V