Mechanics | Relativity Answers

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?

A particle perform simple harmonic motion in a straight line about a center C in the line.When it's distances from C are 5.0 and 13.0cm,it's velocities are 25.0 and 7.0cm/s respectively.Find the period and the amplitude of the oscillation. Hint: use V=±w(angular velocity)√(A² - y²) and solve simultaneously.?

An object is projected with a velocity U at an angle R to the horizontal.It just clears two walls of equal height b and at a distance of b apart. Show that 2U cosR√(U² sin²R - 2bg) = bg?

A car of mass 8000kg moves in a circular path of radius 100m with a linear velocity of 50m/s.Calculate the i) Angular velocity ii) Angle the tyre makes with the ground iii) condition for skidding for u(coefficient of friction)= 0.5?

It is known that the mass of the earth is 81 times the mass of the moon.Show that the point of weightless between the earth and the moon for a spacecraft occur at 9/10 of the distance to the moon Hint: Me/b²=Mm/(a-b)²?

1.Calculate the Support Moment of the shoulder for a worker holding a 3kg drill at shoulder height. The length of the worker’s arm is .85m. Gravity=9.81m/s²

a.What joint is the axis of rotation?

b.What is the force (N) of the load?

c.What is the distance of the load from the axis of rotation?

d.What is the Moment of force of the load on the body?

e.What is the Support Moment the shoulder must exert to avoid movement?

A particle perform simple harmonic motion in a straight line about a center C in the line.When it's distances from C are 5.0 and 13.0cm,it's velocities are 25.0 and 7.0cm/s respectively.Find the period and the amplitude of the oscillation. Hint: use V=±w(angular velocity)√(A² - y²) and solve simultaneously.?

An observer sees 2 spaceship flying apart with speed 0.99c. What is the speed of 1 spaceship viewed by other

This exercise is included to exercise your ability to communicate about kinematics in 2

spatial dimensions. This classic class of kinematics problems is known as projectile motion.

A cannon ball is fired across a level field with an initial speed of 15m/s at an angle of 30◦ above

the horizontal. Given that the acceleration of the cannon ball is 9.8 m

s2 downward for the entire

flight of the ball,

questions to be answered:

1)construct a reference frame

2)construct a vector equation describing the coordinates of the cannon ball as a function of time

3) construct a system of equations describing the coordinates of the cannon ball as a function of time

4)eliminate time from that system of equations to show that the path of the cannon ball is

parabolic

5) calculate the time at which the ball strikes the ground (using your coordinate system)

6) calculate the horizontal distance covered by the ball before it strikes the ground. This is

called the range of the projectile.