Mechanics | Relativity Answers

A uniform 5.0 m long ladder of mass 25 kg leans against a frictionless wall at an angle of 62 degrees with the floor. Determine the minimum coefficient of static friction needed on the floor for the ladder not to slide.

a tricycle moves from A to B 250km away at 60km/. It picks another set of passenger to point C 70km away from B at a deduced speed of 40km/h before returning to the park for the day at B in another 1 hour determine (a) the average speed (b) the average velocity

A steel axle carries two railway wheels at a distance 1.448 m apart at 20oC. Calculate the spacing at 2.3oC and 32.3oC and determine the difference in spacing of the wheels at the two different temperatures (spacing at 32.3oC less spacing at 2.3oC )

(The thermal expansion coefficient of steel is (12 x 10-6) oC-1

Give your answer in mm to 2 decimal place.

A tennis player throws a ball vertically upwards at 4.75 m/s. How high does the ball raise above their hand (assuming the hand has not moved since releasing the ball)?

Assume a gravitational acceleration of g = 9.8 m/s2 and give your answer in meters to 2 decimal places.

A person is swinging around a horizontal circle at the end of a rope on a fairground ride. The person weighs 86 kg, at the radius of the circle is 5.3 m. The rope is taut and horizontal as the person swings around at a constant speed of 7.9 m/s

What is the tension force in the rope in Newtons? Give your answer to the nearest whole number?

A machine is mounted on springs. When operating, the base of the machine is found to be vibrating up and down with a period of 271.5 ms. The displacement of the machine base from its equilibrium height, h, varies as:

h(t) = A sin (ωt)

where A = 0.22 mm is the amplitude of the vibration, and ω is the angular frequency of the vibration.

What is the height of the machine above its equilibrium position at a time, t = 5.7 s?

Give your answer in mm to two decimal places. Note that the height relative could be positive or negative and you have enter the negative sign if it is negative.

A train travelling a long a straight track starts from rest a t point A and accelerate uniformly to 20m/s in 20 sec . It travelsat this speed for 60 seconds then slows down unifromly to rest in 40 seconds at point C. It stays at rest at C for 30 sec then reverse directing accelerating uniformly to 10m/s in 10 sec. It travels at this speed for 30 sec then slows down uniformly to rest 10 sec when it reaced Poin B. Plot a graph of a motion of a train?

In auto racing, a crash occurs. A red car hits a blue car from the front with a force of 4000 N. A yellow car also hits the blue car from the side with a force of 5000 N. What is the total force on the blue car?

we were asked to find the time taken for a ball to reach a specific point B. The abscissa of point B is 2m. the acceleration is -4, the initial velocity is 5, and the velocity at B is 3. I used the formula from the time equations that says that x=at^2/2+V initial * t + x initial. i got two answers for time, one which is 2 s and the other is 0.5 s. My teacher used another way and got only 0.5 seconds. Why is 2 seconds rejected?

Derive the analogues effective force relation in rotating frame and explain all the
terms and discuss circumstances where some of these terms vanishes for different
settings.