Answer: d. The helicopter rotor will spin 36,000 times in 1 hour
Step-by-step explanation:
Option A is wrong because in 40 minutes the rotor will spin:
= 40 * 600
= 24,000 times
Option B is wrong because we cannot know the number of times the rotor will spin before being lifted off of the ground with the details given.
Option C is wrong because in 3 hours the rotor will spin:
= 600 * 3 * 60 minutes
= 108,000 times
Option D is correct because in 1 hour the rotor will spin:
= 600 * 1 * 60 mins
= 36,000 times
Answer:
Area of the sector
Step-by-step explanation:
Area of a circle with the given angle and radius is:
=
Putting the values in the formula:
The area of the sector
B a negative and a negative is a positive
Answer:
B. The value of C is 1
Step-by-step explanation:
Given:
- y = 2x + C is a tangent to parabola y² = 8x
To find:
A line being a tangent to curve means both equations are equal but there has to be only one interception between both graphs.
Therefore, substitute y = 2x+C in y² = 8x:
Expand the expression (2x+C)² using perfect square:
Simplify the equation:
The discriminant says:
- If b²-4ac > 0 then there are two real roots
- If b²-4ac = 0 then there is only one real root
- If b²-4ac < 0 then the are no real roots
For this, we choose b²-4ac = 0 since tangents only have one intersection.
Solve the equation for C:
Therefore, the value of C is 1
Answer:
No -3 would not be a solution to this problem, an solution for this would be 9