from rest
dist = 1/2 accn timextime
=1/2 3.2 32.8x32.8
about 1.6x900 m/s ... 1350m
Answer:
D
Explanation:
By law of conservation of momentum:
momentum before collision = momentum after collision

Initial speed of bullet is unknown whereas initial speed of pendulum will be zero as it was at rest.
Final speed of bullet and pendulum will be equal as bullet is embedded in pendulum and both moves together a vertical distance of 6.89cm.
Using third equation of motion:

where:

Thus by placing values 
this speed will be final speed of collision for the calculation of initial speed of bullet.
Putting values:

This 224m/s = 0.224Km/s which is closest to D
Answer:
Required energy = 4758 J
Explanation:
Specific heat capacity of a material is the amount of energy required to raise the temperature of one kilogram (kg) of that material through one degree Celsius (°C).
Given data :
Specific heat capacity = c = 2440 J/kg.°C
Mass = m = 150 g = 0.15 kg
Initial temperature = 22°C
Final temperature = 35°C
Change in Temperature = ΔT = 13°C
Energy = E = ?
Using the following formula and substituting the values, we get:
E = m × c × ΔT
E = 0.15 × 2440 × 13
E = 4758 J
The heat in the air ballon from the flame will create moisture in the ballon and make it rise
Explanation:

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