Answer:

Explanation:
The rate of volume flow out of tank can be expressed as:

where,
dV/dt = Volume flow rate
A = Cross-sectional area of outlet = πd²/4
d = diameter of circular outlet
dL = Displacement covered by water
dt = time taken
but we know that:
Velocity = υ = displacement/time = dL/dt
Substituting the values of "dL/dt" and "A" in the equation, we get:

This is the expression for volume flow rate dV/dt, on terms pf v, d.
F_P + F_Q = M g
F_P = M g - F_Q
Torque, or moment of force:
∑ M_P = 0
∑ M_P = M g L - F_Q · 3 L
0 = M g L - 3 F_Q L / : L
0 = M g - 3 F_Q
3 F_Q = M g
F_Q = M g /3
Finally:
F_P = M g - M g/3
F_P = 4 M g / 3
Question: calculate their densties in Si unit.
200mg,0.0004m³
Answer:
0.5 kg/m³
Explanation:
Applying,
D = m/V........................ Equation 1
Where D = density, m = mass, V = volume.
From the question,
Given: m = 200 mg = (200/1000000) kg = 2.0×10⁻⁴ kg, V = 0.0004 m³ = 4.0×10⁻⁴ m³
Substitute these values into equation 1
D = (2.0×10⁻⁴ kg)/(4.0×10⁻⁴)
D = 2/4
D = 0.5 kg/m³
Hence the density in S.I unit is 0.5 kg/m³
Answer:
Option C, The total momentum of the fragments is equal to the original momentum of the firecracker.
Explanation:
Kinetic energy of cracker cannot remain constant before and after explosion. It is so because in the process of burning and bursting some amount of kinetic energy is lost in the form of light and heat energy. While the total mass before and after the explosion remains constant due to which the momentum is conserved before and after the explosion
Hence, option C is correct
Answer:
Explanation:
Let fuel is released at the rate of dm / dt where m is mass of the fuel
thrust created on rocket
= d ( mv ) / dt
= v dm / dt
this is equal to force created on the rocket
= 220 dv / dt
so applying newton's law
v dm / dt = 220 dv / dt
v dm = 220 dv
dv / v = dm / 220
integrating on both sides
∫ dv / v = ∫ dm / 220
lnv = ( m₂ - m₁ ) / 220
ln4000 - ln 2500 = ( m₂ - m₁ ) / 220
( m₂ - m₁ ) = 220 x ( ln4000 - ln 2500 )
( m₂ - m₁ ) = 220 x ( 8.29 - 7.82 )
= 103.4 kg .