Mechanics | Relativity Answers

The length of the flat 2.4 kg rod is 1.2 m. The rod is attached the other end with a joint so that it can rotate freely. In the initial situation, the rod is held stationary horizontally. a) what is the angular acceleration of the rod at α release? b) what are the rods tangential accelerations of tip and center of gravity at? c) if the rod tip would there be a coin free, so what would happen to it at the time of release?

The car has 4 tires. Each tire has a mass of 25 kg and a diameter of 75 cm. The total weight of the car is 1200 kg and moves at 120 km / h. How much of the total rotational energy of the tires is the energy of the car? Tires can be treated as a flat circle.

The radius of the semicircular trough in the image is 5.0 m
is D = 10 cm and the moment of inertia is J = mD2 / 8, rolls by rotation and non-slip in the trough. The roll coefficient is zero, and there is no air resistance.
a) What is the speed of spinning of the ball at the lowest point of the trough?
b) How high is the ball rising on the opposite side?

The coordinate of a particle in meters is given by x(t) = 16t - 3.0t^3, where the time t is in seconds. The particle is momentarily at rest at t=?

A 71-kg water skier is being accelerated by a ski boat on a flat ("glassy") lake. The coefficient of kinetic friction between the skier's skis and the water surface is μk = 0.26 .
Part A
What is the skier's acceleration if the rope pulling the skier behind the boat applies a horizontal tension force of magnitude FT = 270 N to the skier (θ = 0∘)?
Part B
What is the skier's horizontal acceleration if the rope pulling the skier exerts a force of FT = 270 N on the skier at an upward angle θ = 12∘?

As shown in (Figure 1), five balls (masses m1 = 2.20kg, m2 = 2.15kg, m3 = 2.12 kg , m4 = 2.05 kg , m5 = 2.00kg) hang from a crossbar. Each mass is supported by "5-lb test" fishing line which will break when its tension force exceeds 22.2 N ( = 5.00 lb). When this device is placed in an elevator, which accelerates upward, only the lines attached to the 2.05 kg and 2.00kg masses do not break.
Within what range is the elevator's acceleration?

A crate is given an initial speed of 3.4 m/s up the 28.5 ∘ plane shown in (Figure 1). Assume μk = 0.12.
Part A
How far up the plane will it go?
Part B
How much time elapses before it returns to its starting point?

Two masses mA = 1.0 kg and mB = 7.0 kg are on inclines and are connected together by a string as shown in (Figure 1). The coefficient of kinetic friction between each mass and its incline is μk = 0.30.
If mA moves up, and mB moves down, determine their acceleration. Ignore masses of the (frictionless) pulley and the cord.

An airplane whose air speed is 613 km/h is supposed to fly in a straight path 30.0 ∘ north of east. But a steady 86 km/h wind is blowing from the north.
In what direction should the plane head?

An airplane is heading due south at a speed of 620 km/h . A wind begins blowing from the southwest at a speed of 105 km/h (average).
In what direction should the pilot aim the plane so that it will fly due south?