Horizontal Motion
In a horizontally launched projectile, what variables are zero in the equations?
viy, ax
In a projectile launched at an angle, what variables are zero in the equations?
What is ax
Sue whirls a yo-yo horizontally above her head . What is the direction of the force that acts on the yo-yo?
along the string towards the center of the circle.
Give an example of an object that exhibits simple harmonic motion.
Pendulum Swings: For small angular displacements (less than ~15°), a pendulum exhibits SHM as it swings back and forth under the influence of gravity.OpenStax
Child on a Swing: A playground swing behaves like a pendulum, and for small swings, the motion approximates SHM.
Vibrating Guitar Strings: When plucked, guitar strings vibrate in SHM, producing musical notes.quarkscience.com+3PHYSICS CALCULATIONS+3StudiousGuy+3
Tuning Forks: Striking a tuning fork causes its prongs to oscillate in SHM, emitting a pure musical tone.quarkscience.com
Car Shock Absorbers: The suspension system in vehicles uses springs and dampers to absorb shocks, where the springs can exhibit SHM when compressed or stretched.
Sam throws a baseball horizontally from the top of a cliff. If Sam throws the baseball with higher speed, how will the time it takes to hit the ground be affected? how will the horizontal distance be affected?
No change in time. The time it takes to hit the ground only depends only on vertical velocities and acceleration. Higher horizontal speed, longer horizontal distance.
A batter hits a pop-up straight up over home plate at an initial velocity of 20 m/s. The ball is caught by the catcher at the same height that it was hit. At what velocity will the ball land in the catcher's mitt?
What is -20 m/s where the - sign indicates down.
Sue is swinging a yo-yo around her head. What happens to the size of the centripetal acceleration if the mass of the yo-yo is doubled without changing the period or length of the string?
nothing the size of it is independent of the mass.
Define mechanical resonance and explain how this relates to simple harmonic motion.
Mechanical resonance is a phenomenon that occurs when a mechanical system is subjected to a periodic external force at a frequency that matches the system's natural frequency of vibration.
Resonance is closely related to SHM because it involves driving a system that naturally exhibits SHM at its natural frequency. When the driving frequency matches the natural frequency of the system, the amplitude of oscillation increases significantly, leading to resonance.
A stone is thrown horizontally at +15 m/s from the top of a cliff that is 44 m high. How long does it take the stone to reach the bottom of the cliff? (sig figs)
3.0 seconds
The initial velocity of the ball is 4.47 m/s at an angle of 66 degrees. find how long it took the ball to land.
0.833 s
It takes a 615 kg car 14.3 seconds to travel at a uniform speed around a circular racetrack of 50.0 m radius. What is the acceleration of the car?
9.65 m/s2
What is the difference between the period and the amplitude of a pendulum?
Definition: The period is the time it takes for a pendulum to complete one full back-and-forth swing.
Definition: The amplitude is the maximum angular displacement from the pendulum's equilibrium (rest) position. It represents how far the pendulum swings on either side.
A steel ball rolls with constant velocity across a tabletop .950 m high. It rolls off and hits the ground +0.352 m horizontally from the edge of the table. How fast was the ball rolling?
.800 m/s
A player kicks a football from ground level with a velocity of 27.0 m/s at an angle of 30.0 degrees. What is its maximum height?
9.3 m
Sue whirls a yo-yo in a horizontal circle. The yo-yo has a mass of 0.20 kg and is attached to a string 0.80 m long. If the yo-yo makes 1.0 complete revolutions each second, what force does the string exert on it?
6.3 N
When an object is vibrating on a spring and passes through the equilibrium position, there is no net force acting upon it. Why is the velocity not zero at this point? What quantity is zero?
Despite the absence of net force and acceleration, the object possesses maximum velocity at the equilibrium position. This is because, as the object moves toward equilibrium from either side, it accelerates due to the restoring force. By the time it reaches the equilibrium position, it has gained maximum kinetic energy and, hence, maximum speed. After passing through equilibrium, the restoring force reverses direction, decelerating the object until it momentarily stops at the maximum displacement on the opposite side.
An airplane traveling 1001 m above the ocean at 125 km/h is to drop a box of supplies to shipwrecked victims below. What is the horizontal distance between the plane and the victims when the box is dropped?
496 m
A baseball is hit at 30.0 m/s at an angle of 53.0 degrees with the horizontal. Immediately an outfielder runs 4.00 m/s toward the infield and catches the ball at the same height it was hit. What was the original distance between the batter and the outfielder.
108 m
Friction provides the centripetal force necessary for a car to travel around a flat circular race track. What is the maximum speed at which a car can safely travel around a circular track of radius 80.0 m if the coefficient of friction between the tire and the track is .30
15 m/s
Find the length of a pendulum oscillating on the moon that would have the same period as a 1.0 m pendulum oscillating on earth. The gravity on the moon is about 1/6 of Earth's gravity.
0.16 m