Mechanics | Relativity Answers

A 30 kg block is pushed up an inclined plane at an angle of 25° with a constant velocity of 4 m/s by a force of 280 N parallel to the plane.

What is the coefficient of kinetic friction between the block and the plane?

A uniform 10 kg ladder 2.5 m long is placed against a frictionless wall with its base on the ground 80 cm from the wall.

Find the magnitude of the force exerted on the wall and on the ground.

A 75 kg man is able to climb up 15 m in a 20 m ladder before it slips. What must be the coefficient of friction if the ladder is arranged so that its base makes at an angle of 50⁰ with the ground? Assume the ladder to be uniform and weighing 100 kg.

4. A uniform 15 kg ladder 3 m long rests against a frictionless wall at a point

2.4 m off the floor. Find the horizontal and vertical components of the force exerted by the ladder on the floor.

A satellite has a mass of 100 kg and is located at 2 X10⁶ m above the surface of the Earth.

a) What is the Potential energy associated with the satellite at this location?

b) What is the magnitude of the gravitational force on the satellite?

Solve the resultant and direction of the forces given by component and closed polygon method force 1= 100 grams, due east force 2= 120 grams 30° south of west force 3= 80 grams, 45° South of East?

A 100 kg object is taken to a height of 300 km above the Earth’s surface.

What is the object’s mass at this height?

What is the object’s weight at this point?

From the known mass and radius of the moon, compute the value of the acceleration due to gravity, gM at the surface of the moon.

(mass of the moon M = 7.35 X10²² kg) ( G = 6.67 X10⁻¹¹ Nm²/kg² )

(radius of the moon R = 1.7374 X10⁶ )

On an old 45 rpm record, the beginning track is 8 cm from the center and the

end track is 5 cm from the center.

What are the angular speeds and

the tangential speeds at these distances when the record is spinning at 45 rpm?

In an explosive volcanic eruption, a molten rock spewed _ out from the craterof the volcano reaches a maximum height of 2.481 km above ground. After 37.0 since it WaS released, it hit the ground, distance 5.25 km away from the crater: How much time did it took the molten rock "iio t0 reach the maximum height? () What is the magnitude and direction of the velocity of the molten rock as it was Ay thrown out from the crater? (c) How high is the volcano? 5.25 km (d) What is the magnitude and direction of the velocity of the molten rock when it landed on the ground?