Complete Question
The angular speed of an automobile engine is increased at a constant rate from 1120 rev/min to 2560 rev/min in 13.8 s.
(a) What is its angular acceleration in revolutions per minute-squared
(b) How many revolutions does the engine make during this 20 s interval?
rev
Answer:
a
b
Explanation:
From the question we are told that
The initial angular speed is 
The angular speed after 
is 
The time for revolution considered is 
Generally the angular acceleration is mathematically represented as
=> 
=>
Generally the number of revolution made is is mathematically represented as
=> 
=>
To find the impulse you multiply the mass by the change in velocity (impulse=mass×Δvelocity). So in this case, 3 kg × 12 m/s ("12" because the object went from zero m/s to 12 m/s).
The answer is 36 kg m/s
Answer:
B. 17.15 watts
Explanation:
Given that
Time = 10 seconds
height = distance = 0.7 meters
weight of sack = mg = F = 245 newtons
Power = work done/ time taken
Where work done = force × distance
Substituting the given parameters into the formula
Work done = 245 newton × 0.7 meters
Work done = 171.5 J
Recall,
Power = work done/time
Power = 171.5 J ÷ 10
Power = 17.15 watts
Hence the power expended is B. 17.15 watts
Answer:
90°
Explanation:
The angle will be 90° when momentum for a system can be conserved in one direction while not being conserved in another.
The example can be
If we apply force on an object horizontally in west direction, then as in other direction south or north we cannot apply the principal of momentum conservation.
