"Fig is attacted with answer"
Answer:
a) d = 33.72 m
b) 
= 26 m/s
c) β = 71.08°
Explanation:
a)
When an object is thrown into the air under the effect of the gravitational force, the movement of the projectile is observed. Then it can be considered as two separate motions, horizontal motion and vertical motion. Both motions are different, so that they can be handled independently.
Given data:
time = t = 4.00 s
Height = h = 20 m
Angle = θ = 60°
Horizontal distance = d = ?
Using 2nd equation of motion
-20 = 
(4) + 0.5(-9.8)(4)²
(4) = 58.4
= 14.6 m/s
This is vertical component of velocity when the ball is on the roof. To calculate the Final velocity and horizontal component, we use
= / sinθ
= 14.6 / sin 60
= 16.86 m/s
= cosθ
= 16.86 cos 60
= 8.43 m/s
To calculate the horizontal distance
d = t
d = (8.43)(4)
d = 33.72 m
b)
We know the values of Landing angle, height of roof, time of flight. In part a, We calculate the landing velocity of the ball and also its horizontal and vertical component. As the ball followed the projectile path, and we know that in projectile motion the horizontal component of the velocity remain constant throughout his motion. So there is no acceleration along horizontal path.
So,
= 
but the vertical component of velocity vary with and there is an acceleration along vertical direction which is equal to gravitation acceleration g.
So,
g = ( - 
) / t
9.8 = 14.6 - ) / 4
= 24.6 m/s
= 
= 
= 26 m/s
c)
cos β = /
β = cos⁻¹ (8.43 / 26)
β = 71.08°
Here it is an application of Newton's III law
as we know by Newton's III law that every action has equal and opposite reaction
So here as we know that two boys jumps off the boat with different forces
from front side of the boat the boy jumps off with force 45 N which means as per Newton's III law if boy has a force of 45 N in forward direction then he must apply a reaction force on the boat in reverse direction of same magnitude
So boat must have an opposite force on front end with magnitude 45 N
Now similar way we can say
from back side of the boat the boy jumps off with force 60 N which means as per Newton's III law if boy has a force of 60 N in backward direction then he must apply a reaction force on the boat in reverse direction of same magnitude
So boat must have an opposite force on front end with magnitude 60 N
So here net force due to both jump on the boat is given by
so boat will have net force F = 15 N in forward direction due to both jumps
Answer:
D. shortest wavelength
Explanation:
Photons with the highest energy have the shortest wavelength. The shorter the wavelength, the higher the energy of a photon.
A photon is a quantity that transmits electromagnetic energy from one place to the other.
- Gamma rays have photons that transmits the highest amount of energy.
- The rays have the shortest wavelength and highest frequency of all electromagnetic radiations.
Energy, wavelength and frequency of a photon are connected using the expression:
E = h f = 
E is the energy
h is the Planck's constant
f is the frequency.
Answer:
any object that has density more than 1.4
Explanation:
The object that has density more than 1.4 is denser than the honey
