Mechanics | Relativity Answers

A regulation basketball has a 50 cm diameter
and may be approximated as a thin spherical
shell.
How long will it take a basketball starting
from rest to roll without slipping 1.9 m down
an incline that makes an angle of 77.0
◦ with
the horizontal? The acceleration of gravity is
9.81 m/s
2
.
Answer in units of s.

a student pushed a box 16.0 m across a smooth, horizontal floor using a constant force of 124 N. If the for applied for 8.00 s, how much power did it take to accomplish this task ( to the nearest watt)?

6.A dumbbell consists of two uniform spheres of mass M and radius R joined by a thin rod of mass m. The distance between the centers of the spheres is l as shown in the figure. What is the moment of inertia of this device about an axis through the center of the rod perpendicular to the rod? About an axis along the rod?

2.Inelastic Collision. Two automobiles of 540 and 1400 kg collide head-on while

moving at 80 km/h in opposite directions. After the collision the automobiles remain locked together.

(a)Find the velocity of the wreck immediately after the collision.

(b)Find the kinetic energy of the two-automobile system before and after the collision.

(c)The front end of each automobile crumples by 0.60 m during the collision. Find the acceleration (relative to the ground) of the passenger compartment of each automobile;
make the assumption that these accelerations are constant during the collision.

A student lifts 100 N of books 1 m to his shoulder. He walks forward 10 m to the stairs and goes up 3 m. He walks 20 m forwards to class. How much work has been done to the books?

Stewart Dent is asked to measure the density of a piece of iron. He measures the mass of the iron and records a value of 97.4g. He measures the volume of water in a graduated cylinder as 50.4mL, after submerging the iron , the volume is 63.3mL .if tje actual density of iron is 7.874g/mL what is Stewart's %-error?

A car is travelling at a constant speed of 45 m/s passes a topper behind a billboard. one second of the car passes the billboard the trooper sets out from the billboard to catch it,accelerating at a constant speed of 3 m/s. how long does it take her to overtake the car?

A jet lands on a aircraft carrier at 140 mile (63 m/s)
(a)what is its acceleration if it stops in 2 second?
(b)what is the displacement of the plane.which it is stopping?

A simple pendulum has a length of 1.5m and a bob of mass 0.2kg. If the amplitude of oscillation of the bob is 0.05m, calculate period of oscillation

A telephone pole has three cables pulling as shown from above, with F⃗ 1=(300.0iˆ+500.0jˆ) F⃗ 2=−200.0iˆ F⃗ 3=−800.0jˆ. (a) Find the force on the telephone pole in component form. (b) Find the magnitude and direction of this net force.