The mass of the bird is 0.32 kg.
<u>Explanation:</u>
Gravitational potential energy, the energy exhibited by an object at rest due to the influence of gravitational force. So the increase in distance of object from the surface of earth leads to increase in the gravitational potential energy. Thus,

So, as the gravitational potential energy is given as 2033 J and the position of bird placed on the tall tower is 639 m away from the bottom, then the mass (m) of the bird can be found as below.

So, finally we get the bird's mass as,
m of bird = 0.32 kg
Answer:
Chemical to kinetic and thermal.
Explanation:
You would eat the food (chemical) than you would jog and move around (kinetic). While running your body would also give off heat (thermal).Than your body would sweat to cool itself down.
Answer:The frequency of the echo is slightly decreased
Explanation:
Given
speed of boat 
cliff is
away
when boat is still , suppose t is the time taken by the echo to reach observer on the boat
But as soon as boat starts moving the distance between cliff and boat decreasing and time for echo to reach observer also decreases
and we know 
therefore frequency of the echo slightly decreased.
Answer:
- 0.6
Explanation:
Given that angle between normal y axis is 62° so angle between normal
and x axis will be 90- 62 = 28 °. Since incident ray is along x axis , 28 ° will be the angle between incident ray and normal ie it will be angle of incidence
Angle of incidence = 28 °
angle of reflection = 28°
Angle between incident ray and reflected ray = 28 + 28 = 56 °
Angle between x axis and reflected ray = 56 °
x component of reflected ray
= - cos 56 ( it will be towards - ve x axis. )
- 0.6