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In considering the moment of inertia of a body, it is convenient to assume as if all its mass were concentrated at a single point from the center of rotation. This distance is called ___________
radius of gyration
center of gravity
center of mass
lever arm
Which has a greater moment of inertia?
short, thin leg
long, thin leg
short, fat leg
long, fat leg
If the second group of survivors is located 700m away from the first group and the plane will drop another set of relief goods at the same altitude and speed, wilk it arrive precisely at the survivor's location.?What factors affect the motion of a projectile launched horizontally
The angular velocity of an airplane propeller increases from 12.0 rad/s to 16.0 rad/s while turning through 7.00 rad. What is the angular acceleration in rad/s^2?
1. A 3.0 meters long solid shaft makes an angle of 35 degrees with the horizontal. A vertical
force of 50 N is applied 0.60 m from the upper end. What is the magnitude of the torque
due to the vertical force about each end?
2. A Ladder of 6.0 meters in length weighs 150 N rests on horizontal ground and leans at an
angle of 65 degrees with the horizontal against a smooth vertical wall. How far up the ladder
may a 700 N person go before the ladder slips? The coefficient of friction between ladder
and ground is 0.40.
3. A Flat bar is loaded with boxes as shown in
figure at right. Box M = 50 kg, what must be
the magnitude of mass m so that the bar
becomes level? Neglect the weight of the bar.
What torque about each end of the bar?
7. Find the specific gravity, weight density, and volume of the unknown object if it
weighs 40 Ib in air and 30 Ib in water.
2. A 10,000 kg vehicle will round the having a radius of 150 meter. The curved road is
banked at 25 degrees with the horizontal, find the minimum coefficient of friction.
4. Find the acceleration and the centripetal force of a 14 kN car that rounds the curved
of radius of 50 meters having a speed of 8 km/h.
5. Two perfectly elastic balls, weighing 27 N and 18 N, approach each other with a
speed of 6 m/s and 11 m/s, respectively. What is the speed of the balls after the
collision?
In a relay race, each contestant runs 25.0 m while carrying an egg balanced on a spoon, turns around, and comes back to the starting point. Edith runs the first 25.0 m in 20.0 s. On the return trip she is more confident and takes only 15.0 s. What is the magnitude of her average velocity for (a) the first 25.0 m? (b) The return trip? (c) What is her average velocity for the entire round trip? (d) What is her average speed for the round trip?
Earthquake produce several types of shock waves. The most well-known is the P-waves and the S-waves. In the Earth's crust, the P-waves travel at around 6.5 km/s, while S-waves move at about 3.5 km/s. The actual speeds vary depending of the type of material they are going through. The time delay between the arrival of these two waves at seismic recording station tells geologist how far away the earthquake occured. If the time delay is 33 s, how far from the seismic station did the earthquake occur?
A projectile is fired at an angle 15 ° from a gun that is 45 m above the flat ground, emerging
from the gun with a speed of 300 m/s.
(a) How long does the projectile remain in air?
(b) At what horizontal distance from the firing ground does it strike the ground.
(c) What is the velocity of the projectile when it hits the ground?
A particle moves in a straight line such that its displacement, x meters, from a fixed point O
on the line at time t seconds is given by 𝑥 = 60[𝑒
−2𝑡 − 𝑒
−4𝑡
].
(a) Find the time when the particle is instantaneously at rest.
(b) Find the displacement of the particle from O when t = 4 s.
(c) Find the total distance travelled during the first 4 seconds of its motion.
