Exam 5: More Applications of Newtons Laws

A hornet circles around a pop can at increasing speed while flying in a path with a 12-cm diameter.We can conclude that the hornet's wings must push on the air with force components that are

A 2.0-kg block slides on a rough horizontal surface.A force (magnitude P = 4.0 N)acting parallel to the surface is applied to the block.The magnitude of the block's acceleration is 1.2 m/s².If P is increased to 5.0 N,determine the magnitude of the block's acceleration.

A 60-kg person rides down an icy hill of 20 $\degree$ slope while standing on a 3.0-kg flat-bottomed bathroom scale.Assume there is no frictional force between the bottom of the scale and the hill.The static friction force the scale exerts on the person is

An airplane flies in a horizontal circle of radius 500 m at a speed of 150 m/s.If the plane were to fly in the same 500 m circle at a speed of 300 m/s,by what factor would its centripetal acceleration change?

The following equation was obtained by solving a physics problem: $\frac { \left( 16.0 \frac { \mathrm { m } } { \mathrm { s } } \right) ^ { 2 } } { ( 75.0 \mathrm {~m} ) \left( 9.80 \frac { \mathrm { m } } { \mathrm { s } ^ { 2 } } \right) } = \tan 19.2 ^ { \circ }$ The best physical representation of the situation is

The coefficient of static friction for the tires of a race car is 0.950 and the coefficient of kinetic friction is 0.800.The car is on a level circular track of 50.0 m radius on a planet where $g = 2.45 \frac { \mathrm { m } } { \mathrm { s } ^ { 2 } }$ compared to Earth's $g = 9.80 \frac { \mathrm { m } } { \mathrm { s } ^ { 2 } }$ .If the car is to be able to travel at the same speed on the planet as on Earth,the radius of the track on the planet must be ____ times as large as the radius of the track on Earth.

A split highway has a number of lanes for traffic.For traffic going in one direction,the radius for the inside of the curve is half the radius for the outside.One car,car A,travels on the inside while another car of equal mass,car B,travels at equal speed on the outside of the curve.Which statement about resultant forces on the cars is correct?

A car travels along the perimeter of a vertical circle (radius = 0.25 km)at a constant speed of 30 m/s.What is the magnitude of the resultant force on the 60-kg driver of the car at the lowest point on this circular path?

A 0.50-kg mass attached to the end of a string swings in a vertical circle (radius = 2.0 m).When the string is horizontal,the speed of the mass is 8.0 m/s.What is the magnitude of the force of the string on the mass at this position?

Two blocks in contact with each other are pushed to the right across a rough horizontal surface by the two forces shown.If the coefficient of kinetic friction between each of the blocks and the surface is 0.30,determine the magnitude of the force exerted on the 2.0-kg block by the 3.0-kg block.

Two blocks connected by a string are pulled across a horizontal surface by a force applied to one of the blocks,as shown.The coefficient of kinetic friction between the blocks and the surface is 0.25.If each block has an acceleration of 2.0 m/s² to the right,what is the magnitude F of the applied force?

An airplane flies in a horizontal circle of radius 500 m at a speed of 150 m/s.If the plane were to fly in the same 1 000 m circle at a speed of 300 m/s,by what factor would its centripetal acceleration change?

An iceboat is traveling in a circle on the ice.Halfway around the circle the sail and the steering mechanism fall off the boat.Which statement is correct?

The block shown is pulled across the horizontal surface at a constant speed by the force shown.If M = 5.0 kg,F = 14 N and $\theta$ = 35 $\degree$ ,what is the coefficient of kinetic friction between the block and the horizontal surface?

For a plane to be able to fly clockwise in a horizontal circle as seen from above,in addition to exerting a force downwards on the air

The coefficient of static friction for the tires of a race car is 0.950 and the coefficient of kinetic friction is 0.800.The car is on a level circular track of 50.0 m radius on a planet where $g = 2.45 \frac { \mathrm { m } } { \mathrm { s } ^ { 2 } }$ compared to Earth's $g = 9.80 \frac { \mathrm { m } } { \mathrm { s } ^ { 2 } }$ .The maximum safe speed on the track on the planet is ____ times as large as the maximum safe speed on Earth.

Two blocks are accelerated across a horizontal frictionless surface as shown.Frictional forces keep the two blocks from sliding relative to each other,and the two move with the same acceleration.If F = 1.2 N and M = 1.0 kg,what is the horizontal component (frictional force)of the force of the large block on the small block?

A 0.40-kg mass attached to the end of a string swings in a vertical circle having a radius of 1.8 m.At an instant when the string makes an angle of 40 degrees below the horizontal,the speed of the mass is 5.0 m/s.What is the magnitude of the tension in the string at this instant?

An object attached to the end of a string swings in a vertical circle (R = 1.2 m),as shown.At an instant when $\theta$ = 30 $\degree$ ,the speed of the object is 5.1 m/s and the tension in the string has a magnitude of 20 N.What is the mass of the object?

A race car starts from rest on a circular track of radius 400 m.Its speed increases at the constant rate of 0.500 m/s².At the point where the magnitudes of the radial and tangential accelerations are equal,determine (a)the speed of the race car,and (b)the elapsed time.