Answer:
Explanation:
Given
mass of car 
Initial velocity of car
towards east
Time taken to stop 
Force exerted 
change in momentum is given by impulse imparted to the car



negative Sign indicates that impulse is imparted opposite to the direction of motion
magnitude of momentum 
Answer:
3 photons
Explanation:
The energy of a photon E can be calculated using this formula:

Where
corresponds to Plank constant (6.626070x10^-34Js),
is the speed of light in the vacuum (299792458m/s) and
is the wavelength of the photon(in this case 800nm).

Tranform the units

The band Gap is 4eV, divide the band gap between the energy of the photon:

Rounding to the next integrer: 3.
Three photons are the minimum to equal or exceed the band gap.
Answer:
4
Explanation:
It has 8 O atoms and 4 O2(g) molecules
Answer:
0.12 K
Explanation:
height, h = 51 m
let the mass of water is m.
Specific heat of water, c = 4190 J/kg K
According to the transformation of energy
Potential energy of water = thermal energy of water
m x g x h = m x c x ΔT
Where, ΔT is the rise in temperature
g x h = c x ΔT
9.8 x 51 = 4190 x ΔT
ΔT = 0.12 K
Thus, the rise in temperature is 0.12 K.
Answer:
(A)The water will freeze.
Explanation:
Heat is the energy that when transferred causes change in temperature. If heat is added to a body by some process the bodies temperature increases and if heat is removed from a body by some process the temperature reduces.
In this case if enough heat is removed from the room the internal movement of the water particles will slow down causing the water to form crystal lattice thus forming ice. So, the water will freeze.