Question

A 35.0-kg dolphin accelerates opposite to the motion from 12.0 to 7.50 m/s in 2.30 s to join another dolphin in play. What average force was exerted to slow the first dolphin if it was moving horizontally? (The gravitational force is balanced by the buoyant force of the water.)

a) 47.0 N
b) 73.9 N
c) 117 N
d) 136 N

Answer 1

To find the average force exerted to slow the dolphin, use Newton's second law of motion, which states that force is equal to mass multiplied by acceleration. The average force exerted on the dolphin is approximately 68.23 N.

Step-by-step explanation:

To find the average force exerted to slow the dolphin, we can use Newton's second law of motion, which states that force is equal to mass multiplied by acceleration. In this case, the mass of the dolphin is 35.0 kg and we can calculate the acceleration using the formula:

acceleration = (final velocity - initial velocity) / time

Plugging in the values, we get: acceleration = (7.50 m/s - 12.0 m/s) / 2.30 s = -1.9565 m/s²

Now, we can calculate the average force using the formula:

force = mass x acceleration

Plugging in the values, we get: force = 35.0 kg x -1.9565 m/s² = -68.23 N

Since the question asks for the average force, we only need to take the magnitude of the force, which gives us an answer of approximately 68.23 N.