Exam 4: Forces and Motion I: Newtons Laws

Three blocks are connected by massless cords and rest on a frictionless horizontal surface. The blocks are pulled to the right. Mass m₁ = 2m₂ = 3m₃, with m₁ on the left and m₃ on the right. If the pulling force is equal to 90 N, then the tension in the cord between m₁ and m₂ is

The SI unit of force is the

A vertical rope is attached to an object that has a mass of 40.0 kg and is at rest. The tension in the rope needed to give the object an upward speed of 3.50 m/s in 0.700 s is

A horse exerts a force F on a cart, causing the cart to move with increasing speed. What force does the cart exert on the horse?

A force accelerates a body of mass M. The same force applied to a second body produces three times the acceleration. What is the mass of the second body?

The diagrams below show the application of a net force F on a block of mass m. Which diagrams) produces the largest acceleration on the block in the horizontal direction?

You are riding an elevator that is in motion. Using a spring balance calibrated in newtons, you notice that a 10.0 kg hanging mass reads 120 N on the scale. What is the acceleration of the elevator?

Three forces, , , and , act on a mass of 4.2 kg. The forces are = 2.0 N acting to the east, = 5.0 N acting 45^o to the north of east, and = 4.0 N acting 30^o to the north of west.The direction of the net acceleration

A mass 2m is attached by a string to another mass m as illustrated. A force of newtons acts on mass m to accelerate the system. The force in the string, which acts on mass 2m, is

An astronaut lands on an Earthlike planet and drops a small lead ball with a mass of 76.5 g from the top of her spaceship. The point of release is 18 m above the surface of the planet and the ball takes 2.5 s to reach the ground. The astronaut's mass on Earth is 68.5 kg. Her mass on the planet is

The acceleration due to gravity on the Moon is only about 1/6 of that on Earth. An astronaut whose weight on Earth is 600 N travels to the lunar surface. His mass as measured on the Moon is

A ball of mass 2.0 kg is acted on by two forces, , and . The direction of the acceleration vector ) w.r.t to the +x-axis is

A net force is exerted on an object toward the north. The object

The diagrams below show the application of an external force F on a block of mass m resting on a horizontal surface. In which diagrams) does the block experience the smallest normal force?

A ball of mass 2.0 kg is acted on by two forces , and . The acceleration vector, , of the mass is in m/s²)

A boy holds a bird in his hand. The reaction force to the normal force exerted on the bird by the boy's hand is the force of

A boy holds a bird in his hand. The reaction force to the weight of the bird is the force of the

Which of the following free-body diagrams represents the block sliding down a frictionless inclined plane?

A large 15,000-kg) stationary military helicopter lifts a 6000-kg truck straight up out of a danger zone with an acceleration of 4 m/s². Calculate the tension in the lifting cable.

A horse-drawn coach is decelerating at 3.0 m/s² while moving in a straight line horizontally. A 350-g mass is hanging on a string 1.6 m long from the ceiling of the coach. The angle that the string makes with the vertical is