Answer:
a. It always points perpendicular to the contact surface.
Explanation:
"Normal" means perpendicular. Normal forces are always perpendicular to the contact surface.
Explanation:
If we assume negligible air resistance and heat loss, we can assume that all of the Gravitational potential energy of the ball will turn into Kinetic energy as it falls toward the ground.
Therefore our Kinetic energy = mgh = (10kg)(9.81N/kg)(100m) = 9,810J.
Answer:
Check the explanation
Explanation:
net angular momentum is conserved as there is no net external torque.
therefore. 0 = angular momentum of woman + angular momentum of wheel.
0 = 55x2x1.5 + 480xω
ω = -0.3056 rad/sec ,-ve sign shows that the direction is opposite to woman, ie counterclockwise.
work done by woman = total kinetic energy of the wheel and woman
=1/2 x 55 x 1.52 + 1/2 Iω2 = 1/2x55x1.52 + 1/2x540x0.30562= 41.8+73.35 = 115.14J
It is a synthesis reaction where two reactants gives one product.
Answer:option D
2Mg + O2 ------> 2 MgO
Answer:
Doppler shift of the starlight
Explanation:
To predict the movement of a star, we compare the spectra of elements found in star (H, He Na etc.), first spectra which are obtained from star and second spectra from laboratory. If spectral lines of the spectra obtained from star, are shifting towards red end (called red shift) then star is going away from earth and if shifting is towards blue (called blue shift), then star is approaching the earth. This is Doppler's shift.