knowledge of first aid ... eg St John Ambulance, Red Cross etc. I think that everyone in a school should be taught First Aid.
Answer:
Explanation:
Kinetic energy of block will be converted into heat energy by friction .
Heat energy produced = 1/2 m v²
= .5 x 4.8 x 1.2²
= 3.456 J
85% of energy is converted into heat energy , so heat energy produced
= .85 x 3.456 = 2.9376 J .
If Q heat is given to m mass of object having s as specific heat and Δt is increase in temperature
Q = msΔt
specific heat of iron s = 462 J / kg C
Putting the values ,
2.9376 = 4.8 x 462 x Δt
Δt = 13.24 x 10⁻⁴ ⁰C.
Answer:
Explanation:
For free body diagram see attached sheet .
W is weight of steel girder acting at the middle point of its length . T is tension in the cable .
OB = √ ( 12² - 2² )
= 11.83 m .
OC = 11.83 / 2 = 5.915 m
Taking moment of tension T and weight W about point O
W x OC = T x OB
22 x 5.915 = T x 11.83
T = 22 x 5.915 / 11.83
= 11 kN
Considering forces acting in vertical direction and equating forces in opposite direction
T + R = W
R = W - T
= 22 - 11 = 11 KN
So force of grinder on the ground = R
= 11 KN.
Answer:
The angle is 18.3 degree.
Explanation:
A uniformly charged infinite plane, density σ = 4 x 10^-9 C/cm^2, is placed vertically in air. A small ball of mass 8 g, with charge q = 10^-8 C, hangs close to the plane, so that the string is initially parallel to the plane. Take g = 9.8m/s2. When in equilibrium, by what angle is the string hanging the ball to the plane?
surface charge density, σ = 4 x 10^-5 C/m^2
Charge, q = 10^-8 C
mass, m = 0.008 kg
Let the angle is A and the tension in the string is T.
The electric field due to a plane is

Now equate the forces,

The sparse area surrounding a spiral galaxy is called its halo. Hoped this helped!