Hello There!
Relative density is another word for specific gravity. Relative density is comparing the density of one thing to the density of another. Most of the time, you look at the density of water so we look at the density of an object relative to the density of water.
Answer:
(a) An electric iron works on the heating effect of electric current
(b) The heating effect of an electric current is the tendency for electric current to cause the temperature of the material through which it is flowing to rise due to the resistance of the material
The heating effect, 'E', is given by the formula, E = I²·R·t
Where;
I = The current flowing
R = The resistance of the material
t = The time the material takes to heat up
(c) The values showed by Pinki here is the value of care, concern and prevention, to prevent the harmful effect of the high heat on the skin of her daughter
Explanation:
Solution:
The angle between the sling and the load is 
So the tension in each sling can be calculated as
Where
M is the mass of the load
The Horizontal reaction on the sling will be inward.
After using the spreader, the new angle between sling and load is 
, the tension in the sling will be
= 
The tension will be same as before in the sling move away through the spreader at an angle more than 90 degree the horizontal force will act opposite and will be outward
Answer:
A) 1.53s
B) 19.8m
C) 2.869m
Explanation:
A) The time of flight for a projectile can be calculated using the formula:
t = 2μsinθ/g
Where; u = velocity
θ = angle
g = acceleration due to gravity (9.8m/s^2)
t = 2 × 15 × sin 30°/9.8
t = 30sin30°/9.8
t = 30 × 0.5/9.8
t = 15/9.8
t = 1.53s
B) The horizontal range (distance) for a projectile can be calculated using the formula:
Range = u²sin2θ/ g
Range = 15² sin 2 × 30 / 9.8
Range = 225 sin 60/9.8
Range = 225 × 0.8660/9.8
Range = 194.855/9.8
Range = 19.8m
C) The maximum height for a projectile can be calculated using the formula:
h = u²sin²θ/2g
h = 15² (sin 30)² / 2 × 9.8
h = 225 × 0.25 / 19.6
h = 56.25/19.6
h = 2.869m
