Question

1. which force causes objects to fall toward earth?

a. magnetic force
b. normal force
c. gravitational force
d. nuclear force

1. a 20 - n force pushes a 5 - kg box on a frictionless surface. the acceleration is:

a. 1 m/s²
b. 2 m/s²
c. 4 m/s²
d. 5 m/s²

1. a heavy truck collides with a small car. according to newtons third law:

a. the truck exerts more force
b. the car exerts more force
c. they exert equal force on each other
d. no forces act

Explanation:

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Gravitational force is the force that attracts objects towards each other. On Earth, it causes objects to fall toward the Earth. Magnetic force is related to magnets, normal force is the support force perpendicular to a surface, and nuclear force is involved in the nucleus of an atom.

Step1: Recall Newton's second law

Newton's second law is \(F = ma\), where \(F\) is the force, \(m\) is the mass, and \(a\) is the acceleration. We need to solve for \(a\), so the formula becomes \(a=\frac{F}{m}\).

Step2: Substitute the given values

Given \(F = 20\space N\) and \(m=5\space kg\). Substitute into the formula: \(a=\frac{20}{5}\).

Step3: Calculate the acceleration

\(a = 4\space m/s^{2}\)

Newton's Third Law states that for every action, there is an equal and opposite reaction. When two objects collide, the force exerted by the first object on the second is equal in magnitude and opposite in direction to the force exerted by the second object on the first. The size of the objects (truck and car) does not affect the equality of the forces in a collision according to this law.

Answer:

C. Gravitational force

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