Mechanics | Relativity Answers

For a car to safely make around the curve during the course of a turn, an automobile doubles its speed. What frictional force must the tires provide?

Group of answer choices

a. ¼ as big the previous force

b. double

c. ½ as big the previous force

d. quadruple

1.) Two forces act on a 55-kg box on a smooth level path. One force has magnitude 50 N directed 45 degrees clockwise from the positive x-axis, and the other has a magnitude 50 N at 45 degrees counter-clockwise from the positive x-axis. What is the net force that causes the box in motion?

a. 0

b. 50 N along positive x-axis

c. 100 N to the right

d. 70 N east

2.) You are in an elevator, standing on a scale, and stuck on 14th floor due to brownout. What is the scale reading?

a. zero

b. greater than the actual weight

c. actual weight

d. less than the actual weight

3.) A roller-coaster car has a mass of 500 kg when fully loaded with passengers. At the bottom of a circular dip of a radius 40m, the car has a speed of 16 m/s. What is the magnitude of the force of the track on the car at the bottom of the dip?

a. 4.9 kN

b. 3.2 kN

c. 1.7 kN

d. 8.1 kN

A crate slide down a caugo ramp that is inclined at 37 degrees. If the coefficient of the friction between the crate and and the ramp is 0.15, what is the acceleration of the crate? what must the coefficient of the friction be in order for the crates to remains stationary and not to slide on the ramp?

If a is equal to 1.2 ± 0.1cm, b=2.0 ± 0.2cm, c=1.05±0.05cm, calculate the following with the errors and standard errors

(i) ab/C³

(ii) ABC

(iii) C²a³/b²

If a is equal to 1.2 ± 0.1cm, b=2.0 ± 0.2cm, c=1.05±0.05cm, calculate the following with the errors and standard errors

(i) ab/C³

(ii) ABC

(iii) C²a³/b²

If a is equal to 1.2 ± 0.1cm, b=2.0 ± 0.2cm, c=1.05±0.05cm, calculate the following with the errors and standard errors

(i) ab/C³

(ii) ABC

(iii) C²a³/b²

The free-throw line in basketball is 4.57 m from the basket, which is 3.05 mabove the floor. A player standing on the free-throw line throws the ball with an initial speed of 7.15 m/s, releasing it at a height of 2.44 m above the floor. At what angle above the horizontal must the ball be thrown to exactly hit the basket?

Note that most players will use a large initial angle rather than a flat shot because itallows for a larger margin of error.

The rear wheel of a 150 kg tricycle accidentally ran over a nail. The circular tip of the nail has a diameter of 0.001 m. How much pressure did the wheel of the tricycle experience assuming that the entire weight of the tricycle is concentrated on the rear wheel that ran over the nail.

Solve the following problems completely and present your final answers in two (2) decimal places.

1. The rear wheel of a 150 kg tricycle accidentally ran over a nail. The circular tip of the nail has a diameter of 0.001 m.How much pressure did the wheel of the tricycle experience assuming that the entire weight of the tricycle is concentrated on the rear wheel that ran over the nail.
2. A medium sized car typically weighs 1000 kg.

A hydraulic system to jack the car up above an inspection pit hasfour slave cylinderswhose pistons have a cross section area of 0.01 m². The cross-section area of the master cylinder piston is 0.00125 m².

(a) What is the weight of the car?

(b) What is the minimum force that must be applied to the master cylinder to raise the car upwards?

Juliana was observing an ant that crawled along a tabletop. With a piece of chalk she followed its path. She determined the ant’s displacement using a ruler. The displacements were as follows: 7 cm West, then 4 cm North, 7cm East, and finally 4 cm South. How far is the ant from its starting point?