Answer:
A) 5m/s
Explanation:
Momentum of ball in one direction=momentum of cannon in other direction
mv = mv
(10)(500)=(1000)v
5000=1000v
∴v=5m/s
Answer D
In alkali earth metals reacrivity increases from top to bottom (opposite of b)
This is because as you go down, the electron shells increase by 1 shell. The farther away a shell is from the nucleus, the higher its tendency to react.
D is true because the more reactive an alkali metal is, the more vigorous the reaction will be with water.
<u>We are given:</u>
2 Vectors A and B
A = î - 5j
B = 2î - 10j
<u>Proving that the given vectors are Parallel:</u>
We can rewrite the Vector B as: B = 2(î - 5j)
Since A = î - 5j
Vector B can be written as:
B = 2(A vector)
this means that the magnitude of Vector B is twice of vector A but their direction is the same
Since the 2 vectors are moving in the same direction, they are parallel
Answer:
60,000 J
Explanation:
The total Energy in the system = the sum of potential and kinetic energy
Total energy = K. E + P. E
K. E = 0.5mv²
m = mass ; v = velocity, K. E = kinetic energy
V = 20 m/s ; mass = 600kg
Total energy = 180000 J
Hence,
K. E = 0.5 * 600 * 20^2
K.E = 300 * 400
K. E = 120,000
P. E = TOTAL ENERGY - K.E
P.E = I80,000 - 120,000
P.E = 60,000 J