Answer:
180 kJ
Explanation:
Given that:
Mass (m) = 5 kg
Initial temperature (T1) = 28°C
Final temperature (T2) = 68°C
The change in temperature (ΔT) = T2 - T1 = 68°C - 28°C = 40°C
Specific heat capacity of aluminium (c) = 900 J/kg°C
The quantity of heat energy required (q) is given by:
q = mcΔT
q = 5 kg × 900 J/kg°C × 40°C
q = 180000 Joules
q = 180 kJ
Therefore 180 kJ is required to raise the temperature of aluminium from 28°C to 68°C.
Answer:
Because nuclear decay releases ionizing radiation (alpha, beta, and gamma radiation) we call such compounds radioactive.
Explanation:
Answer:
9 m/s
Explanation:
mass of cannon, M = 100 kg
mass of cannon ball, m = 10 kg
velocity of cannon ball, v = 90 m/s
Let the recoil velocity of cannon is V.
Us ethe conservation of linear momentum, as no external force is acting on the system, so the linear momentum of the system is conserved.
Momentum before the firing = momentum after the firing
M x 0 + m x 0 = M x V + m x v
0 = 100 x V + 10 x 90
V = - 9 m/s
Thus, the recoil velocity of cannon is 9 m/s.
Answer with Explanation:
Let rest mass 
at point P at distance x from center of the planet, along a line connecting the centers of planet and the moon.
Mass of moon=m
Distance between the center of moon and center of planet=D
Mass of planet=M
We are given that net force on an object will be zero
a.We have to derive an expression for x in terms of m, M and D.
We know that gravitational force=
Distance of P from moon=D-x
=Force applied on rest mass due to m
=Force on rest mass due to mas M
because net force is equal to 0.
Let 
Then, 
b.We have to find the ratio R of the mass of the mass of the planet to the mass of the moon when x=
Net force is zero
Hence, the ratio R of the mass of the planet to the mass of the moon=4:1
