Mechanics | Relativity Answers

Let B = 5.30 m

 at 60.0°. C

 and A

 have equal magnitudes. The direction angle of C

 is larger than that of A

 by 25.0°. Let A · B = 27.0 m²

 and B · C = 34.5 m².

 Find the magnitude (in m) and direction (in degrees) of A.

A uniform ladder weighing 100 N leans against a smooth vertical wall such that it makes a slope of 1:4. A human stands 2 meters up the ladder and has a mass of 70 kg. If the ladder is 5 m long, Find:

A. The force exerted by the wall on the ladder.

B. The magnitude and direction of the resultant force exerted by the floor on the lower end of the ladde

Consider the vectors, 𝑎⃗ = 5.0𝑖̂+ 4.0𝑗̂− 6.0𝑘̂, 𝑏⃗⃗ = −2.0𝑖̂+ 2.0𝑗̂+ 3.0𝑘̂ and 𝑐⃗ =

4.0𝑖̂+ 3.0𝑗̂+ 2.0𝑘̂.

1.1. Find the vector perpendicular to 𝑎⃗ and 𝑐⃗.________________________________________

1. The number of Bacteria in a particular colony is found to double every 2.25 seconds. If the initial count of bacteria is 12500, what will be the population after 125 seconds?

2. The distance covered by a freefalling object under the action of constant action of gravitational field quadratically varies with time. In a time of 3.0 seconds, a free-falling object covers a 5.0-meter distance. what distance will it cover in 5.0 seconds?

A 70 kg father and a 50-kg mother are at opposite ends of a seesaw 6 m long. Where should their 25-kg son sit so that the seesaw is balanced at the center?*

A 2.0 N, 2.0m long uniform rod is used to suspend various weights. A 2N weight is suspended on one end (point A) and a 5N weight is suspended on the other end (point B). A 2.0N object is suspended 0.5 m from point A and a 1.0N is hanged 0.8 m from point B. How far from the center of the rod shall a 3N weight be placed to balance the rod?*

A student opens his laptop with a 2.5 N force at an angle of 70 degrees against the horizontal. Find the torque on the cover of the laptop if the laptop is 20 cm wide.*

A common Ethiopian cities speed limit is 30km/hr.what is this speed in miles per hour?

A block moves along a horizontal surface with a 0.61 coefficient of kinetic friction. The block is pulled by a rope that exerts a 162 N tension force at 370 above the horizontal. Draw the FBD. Determine the kinetic friction.

At the surface of Jupiter’s moon Io the acceleration due to gravity is g=1.81 m/s2 . A watermelon weighs 44.0 N at the surface of the earth. a) What is the mass on the earth’s surface? b) What are its mass and weight on the surface of Io?