Answer:
Second projectile is 1.4 times faster than first projectile.
Explanation:
By linear momentum conservation
Pi = Pf
m x U + M x 0 = (m + M) x V

Now Since this projectile + pendulum system rises to height 'h', So using energy conservation:
KEi + PEi = KEf + PEf
PEi = 0, at reference point
KEf = 0, Speed of system zero at height 'h'

PEf = (m + M) g h
So,


So from above value of V
Initial velocity of projectile =U

Now Since mass of projectile and pendulum are constant, So Initial velocity of projectile is proportional to the square root of height swung by pendulum.
Which means



U₂ = 1.41 U₁
Therefore we can say that ,Second projectile is 1.4 times faster than first projectile.
The kinetic energy of an object is directly proportional to its mass and the square of its velocity
KE = 1/2 (mv²)
KE = Kinetic Energy
m = mass in kg
v = velocity in m/s
Given:
m = .8 kg
v = 11.2 m/s
Substitute:
KE = 1/2 (.8)(11.2²)
KE = 50.18 J
Answer:
1. Potential hazard
2. Mining opportunity
Explanation:
The two reason, why astronomers are so interested in the discovery of additional Earth-approaching asteroids:
1. Potential hazard: We have proof that the dinosaurs got extinct because of an asteroid/comet strike on Earth. Also we have seen the effects of the Tunguska event and Chelyabinsk tragedy. These are enough to show us that asteroids can be very dangerous and wipe out the life from Earth.
2. Mining Opportunity: We have discovered a lot of asteroids which contains a lot of metal and precious elements. There can be a possibility of mining such asteroids in the future and reducing the burden on Earth.
The fusion reaction that is easiest to accomplish is the reaction between two hydrogen isotopes: deuterium, extracted from water and tritium, produced during the fusion reaction through contact with lithium. When deuterium and tritium nuclei fuse, they form a helium nucleus, a neutron and a lot of energy.
Answer:
changing the direction in which a force is exerted