The head of an industrial machine moves in a straight line horizontally backwards and forwards from a central position. The movement can be modelled using the sine wave d = 80 sin ( pie t), where d is the horizontal distance (in cm) from the central starting position, and t is the time after the machine starts running (in second).

choose the 2 correct statements about the motion of the machine:
a) the maximum distance that the machine head moves horizontally from its central starting position is 80cm
b) the maximum distance that the machine head moves horizontally from its central starting position is 40 cm
c) the machine head will make 50 complete cycles in a minute
d) the machine head will make 30 complete cycles in a minute
e) the machine head will make one complete cycle in half a minute
f) the machine head will make one complete cycle in 2 minutes.

I'm assuming its A and E. Anybody have a better idea if I'm wrong?

To determine the correct statements about the motion of the machine, let's analyze the given sine wave equation: d = 80 sin (πt).

a) The maximum distance that the machine head moves horizontally from its central starting position is 80 cm.
This statement is correct. In the given equation, the coefficient of the sine function is 80, which represents the amplitude or the maximum value of the function. So, the maximum distance the machine head moves horizontally is indeed 80 cm.

b) The maximum distance that the machine head moves horizontally from its central starting position is 40 cm.
This statement is incorrect. As discussed in the previous statement, the amplitude is 80 cm, not 40 cm.

c) The machine head will make 50 complete cycles in a minute.
This statement is incorrect. To determine the number of cycles in a minute, we need to consider the period of the function. The period, denoted by T, is the time taken for one complete cycle. In this case, the period can be calculated using the equation T = 2π/ω, where ω is the angular frequency. In our equation, ω = π, so the period T = 2π/π = 2 seconds. Therefore, in a minute, there will be 60/2 = 30 complete cycles, not 50.

d) The machine head will make 30 complete cycles in a minute.
This statement is correct. As discussed in the previous statement, the period of the function is 2 seconds. In a minute, there are 60 seconds, so the number of complete cycles is 60/2 = 30.

e) The machine head will make one complete cycle in half a minute.
This statement is correct. As calculated before, the period of the function is 2 seconds. Since there are 60 seconds in a minute, half a minute is equal to 30 seconds, which is exactly one complete cycle.

f) The machine head will make one complete cycle in 2 minutes.
This statement is incorrect. As discussed earlier, the period of the function is 2 seconds. Therefore, one complete cycle will occur in 2 seconds, not 2 minutes.

In conclusion, the correct statements about the motion of the machine are: a) the maximum distance that the machine head moves horizontally from its central starting position is 80 cm, and e) the machine head will make one complete cycle in half a minute.