Exam 5: Newtons Laws of Motion

A 5.4-kg mass, placed on a smooth incline and released, begins to slide down the incline. The acceleration of the mass along the incline is 7.1 m/s $2$ . The angle of the incline (relative to the horizontal) is

A particle of mass $5.7 \mathrm {~kg}$ , initially at rest, experiences a time-varying force, $f ( t ) = c t ^ { 2 } + h t$ where $c = 1.3 \mathrm {~N} / \mathrm { s } ^ { 2 }$ and $h = 5.6 \mathrm {~N} / \mathrm { s }$ . What is the acceleration of the particle at time $t = 4$ seconds?

A 3-m-long heavy chain, mass of 30 kg, is lowered at constant speed from a barn loft by a farmer. What is the tension in the chain at its midpoint of 1.5 m from an end?

A 10-kg mass is placed at the top of a smooth incline. The incline makes an angle of 30° with the horizontal. What should be the minimum horizontal acceleration of the incline so that the normal force exerted by the incline (acting on the mass) is zero?

Two masses, 5 kg and 3 kg, are connected by massless string. The two masses are then placed on a smooth incline and released. The acceleration of the two masses along the incline is 2 m/s $2$ . Find the tension in the massless string between the two masses.

A 4-kg mass and a 5-kg mass are in contact with each other while resting on a smooth table. A 20-N external force is applied to the 5-kg mass (in a direction toward the 4-kg mass). The acceleration of the 5-kg mass is

A 1200-N force is required to keep an automobile traveling at 20 m/s. From this, the mass of the car

A catcher stops a baseball traveling at 40 m/s in a distance of 0.10 m. In doing so, she applies an average net force of 1200 N. The mass of the baseball is

A person has a mass of 110 kg on Earth. What is the weight of this person on Jupiter, which has a surface gravity of $2.53 \mathrm {~g}$

A 4-kg mass and a 5-kg mass are in contact with each other while resting on a smooth table. A 20-N external force is applied to the 5-kg mass (in a direction toward the 4-kg mass). The acceleration of the 4-kg mass is

A 7-kg mass slides down a smooth incline. The incline makes an angle of 30° with the horizontal. The acceleration of the mass in the horizontal direction is

A 5-kg mass is pulled up a smooth incline at a constant speed by a rope. The rope is parallel with the surface of the incline. If the incline is 50° relative to the horizontal, the normal force exerted by the incline on the mass is

A woman (mass = 70 kg) steps into an elevator. The elevator accelerates upward at 3 m/s $2$ . The force that the floor of the elevator exerts on the woman is

A heavy cable of length $l$ and linear mass density $\lambda$ (mass/length) hangs vertically from a high bridge. What is the tension in the cable at its midpoint of $l / 2$ ?

An 8-kg mass is pulled across a smooth floor using a rope. The rope makes an angle of 28° with the floor. If the tension in the rope is 45 N, the normal force exerted by the floor on the mass is

A $3.3 \times 10 ^ { 6 }$ -kg rocket in deep space generates a thrust of $1 \times 10 ^ { 7 }$ N. What would be the force acting on a 150-kg astronaut riding in the rocket?

The velocity of a $3.2 - \mathrm { kg }$ particle is given by $v ( t ) = c t ^ { 2 }$ , where $c = 2.1 \mathrm {~m} / \mathrm { s } ^ { 3 }$ . What is the force acting on the particle at time $t = 5$ seconds?

A ball is thrown with some initial velocity at an angle of 42° relative to the horizontal. When the ball reaches its maximum height

A person who weighs 1100 N steps into an elevator. The person steps onto a scale, and the elevator begins to move down to the next floor. During the movement the person has an apparent weight of 950 N. The downward acceleration of the elevator is

An archer pulls the string of her bow back with her hand with a force of 200 N. The two halves of the string (above and below her hand) make an angle of 110° with each other. What is the tension in the string?