Answer:
Explanation:
Even though the minimum temperature is more than the freezing point, Frost was observed on the ground because the ground will cool rapidly as cool air tends to move towards the ground, the temperature of the ground is lower than the atmosphere a few feet above it.
As the thermometer is kept some feet above the ground so ground temperature may be lower than the minimum recorded temperature.
Answer:
a)106.48 x 10⁵ kg.m²
b)144.97 x 10⁵ kgm² s⁻¹
Explanation:
a)Given
m = 5500 kg
l = 44 m
Moment of inertia of one blade
= 1/3 x m l²
where m is mass of the blade
l is length of each blade.
Putting all the required values, moment of inertia of one blade will be
= 1/3 x 5500 x 44²
= 35.49 x 10⁵ kg.m²
Moment of inertia of 3 blades
= 3 x 35.49 x 10⁵ kg.m²
= 106.48 x 10⁵ kg.m²
b) Angular momentum 'L' is given by
L = x ω
where,
= moment of inertia of turbine i.e 106.48 x 10⁵ kg.m²
ω=angular velocity =2π f
f is frequency of rotation of blade i.e 13 rpm
f = 13 rpm=>= 13 / 60 revolution per second
ω = 2π f => 2π x 13 / 60 rad / s
L= x ω =>106.48 x 10⁵ x 2π x 13 / 60
= 144.97 x 10⁵ kgm² s⁻¹
P = mv
p = 3.5 × 5
p = 17.5 kg .m/s
Hope this helps!
Answer:
option (E) 1,000,000 J
Explanation:
Given:
Mass of the suspension cable, m = 1,000 kg
Distance, h = 100 m
Now,
from the work energy theorem
Work done by the gravity = Work done by brake
or
mgh = Work done by brake
where, g is the acceleration due to the gravity = 10 m/s²
or
Work done by brake = 1000 × 10 × 100
or
Work done by brake = 1,000,000 J
this work done is the release of heat in the brakes
Hence, the correct answer is option (E) 1,000,000 J
Answer:
The ball slows down in the air due to an unbalanced force
Explanation:
When player kicks the ball, there are mainly two foces acting on this object: the force made by the player and the opposite force of gravity (which acts with a direction always to the centre of the Earth)
The force applied by the player will be decreasing, while the force of gravity is always constant, this will make that both forces will unbalance, making the football´s speed slow down
