Answer:
Explanation: you would need to divide the two numbers
d = distance traveled by her on her bicycle on a long flat road = 24 kilometer
t = time taken by her to travel distance "d" on her bicycle on a long flat road = 1.2 hours
v = average speed of vivian = ?
we know that average speed is given as
v = d/t
inserting the values in the above formula
v = 24 kilometer / 1.2 hour
v = 20 kilometer/hour
hence the correct choice is
C) 20 km/h
1) At the moment of being at the top, the piston will not only tend to push the penny up but will also descend at a faster rate at which the penny can reach in 'free fall', in that short distance. Therefore, at the highest point, the penny will lose contact with the piston. Therefore the correct answer is C.
2) To solve this problem we will apply the equations related to the simple harmonic movement, hence we have that the acceleration can be defined as

Where,
a = Acceleration
A = Amplitude
= Angular velocity
From a reference system in which the downward acceleration is negative due to the force of gravity we will have to



From the definition of frequency and angular velocity we have to




Therefore the maximum frequency for which the penny just barely remains in place for the full cycle is 2.5Hz
Answer:
v = 6i + 12j + 4k
Explanation:
Find the magnitude of the direction vector.
√(3² + 6² + 2²) = 7
Normalize the direction vector.
3/7 i + 6/7 j + 2/7 k
Multiply by the magnitude of v.
v = 14 (3/7 i + 6/7 j + 2/7 k)
v = 6i + 12j + 4k