Reflection and refraction are two different phenomenons. In case of reflection, wave bounces back into the same medium after incident with the interface of two mediums. Reflection will happen if surface is shiny as well as smooth. If surface is irregular, one will get diffused reflection. Refraction means bending of light when waves travel from one medium to another
Answer:
Explanation:
Given
Object fall from a height of 
Considering initial velocity to be zero i.e. 
using
where v=final velocity
u=initial velocity
a=acceleration
s=displacement


(b)Average acceleration
After falling 45 m, object strike the car and comes to rest after covering a distance of 0.5 m
again using

here final velocity will be zero i.e.
initial velocity 


(c)time taken by it to stop


Answer:
The friend on moon is richer.
Explanation:
The value of acceleration due to gravity changes from planet to planet. So the weight of 1 Newton of gold carries different mass on different places. So we need to calculate the mass of gold that both persons have.
<u>FRIEND ON MOON</u>:
W₁ = m₁g₁
where,
W₁ = Weight of Gold won by friend on moon = 1 N
m₁ = mass of gold won by friend on moon = ?
g₁ = acceleration due to gravity on moon = 1.625 m/s²
Therefore,
1 N = m₁(1.625 m/s²)
m₁ = 0.62 kg
<u>ON EARTH</u>:
W₂ = m₂g₂
where,
W₂ = Weight of Gold won by me on Earth = 1 N
m₂ = mass of gold won by me on Earth = ?
g₂ = acceleration due to gravity on Earth = 9.8 m/s²
Therefore,
1 N = m₁(9.8 m/s²)
m₁ = 0.1 kg
Since, the friend on moon has greater mass of gold than me.
<u>Therefore, the friend on moon is richer.</u>
Answer:
k = 5178.8 N/m
Explanation:
As we know that spring mass system will oscillate at angular frequency given as

now we have

now the maximum acceleration of the spring block system is at its maximum compression state which is given as

here A= maximum compression of the spring
so here in order to find maximum compression of the spring we will use energy conservation as we know that initial total kinetic energy of the car will convert into spring potential energy

here we know that
v = 85 km/h

now we have


now from above equation of acceleration we have



Answer:
a
Explanation:
it increases with increasing height