Answer:
(a) Rock: 49 N; Pebble: 2.9 × 10⁻³ N
(b) Rock and pebble: 9.8 m/s²
Explanation:
The question is incomplete. I think this is the original question.
A 5.0 kg rock and a 3.0 × 10⁻⁴ kg pebble are held near the surface of the earth.
(a) Determine the magnitude of gravitational force exerted on each by the earth.
(b) Calculate the magnitude of the acceleration of each object when released.
(a)
We can find the gravitational force using Newton's second law of motion.
F = m . a
where,
m is the mass of the object
a is the acceleration
The acceleration due to the Earth's gravitational force is known as the Earth's gravity and has a value of 9.8 m/s².
Rock
F = 5.0 kg × 9.8 m/s² = 49 N
Pebble
F = 3.0 × 10⁻⁴ kg × 9.8 m/s² = 2.9 × 10⁻³ N
(b)
The acceleration for both objects is that of gravity. We can confirm this using Newton's second law of motion.
Rock
a = F/m = 49 N/5.0 kg = 9.8 m/s²
Pebble
a = F/m = 2.9 × 10⁻³ N/3.0 × 10⁻⁴ kg = 9.66 m/s² ≈ 9.8 m/s²
Here, there is a little error due to the rounding, but it is in essence the same value, which is that of gravity.
