Physics Rotational Mechanics Level: High School
An object with a rotational inertia of 0.15 kgm^2 about an axis is spinning about that axis with an angular velocity of 12 rad/s . The magnitude of the angular momentum of the object is ?a) 1.8 kg m^2 / s
b) 1.5 kg m^2 / s
c) 2.0 kg m^2/ s
d) 1.6 kg m^2 / s
I = 0.15 kgm^2 , W = 12 rad/sL = Iw = 0.15 x 12 = 1.8 kgm^2/s
Physics Rotational Mechanics Level: High School
Find the kinetic energy of a cylindrical shaft of mass 2.0 kg and radius 10 cm rotating about its central axis at 600 rad/s .a) 1200 J
b) 1800 J
c) 12000 J
d) 18000 J
Physics Rotational Mechanics Level: High School
A force of 30 N is applied perpendicular to the face of a door at a distance of 1.5 m from the hinge of the door . Find the torque on the door about its hinge .a) 45 N m .
b) 20 N/m .
c) 2 N m .
d) 20 N m .
Physics Force & Laws Of Motion Level: High School
Impulse
A 200 g ball hits a wall perpendicular with a velocity of 30 m/s and rebounds back with a velocity of 20 m/s if the collision lasts for 5 ms , find the average force exerted by the ball on the wall .a) 1000 N
b) 2000 N
c) 4000 N
d) 6000 N
Physics Work,Power & Energy Level: High School
The unit of work is ?a) kg m/s^2
b) kg m/s
c) kg m^2/s
d) kg m^2/s^2
= kg m/s^2 x m = kgm^2/s^2
Physics Force & Laws Of Motion Level: High School
A 80 kg crate is pulled up a frictionless 300 incline by a rope with an acceleration of 1.5 m/s^2 . If the rope is parallel to the incline what is the tension in the rope ? (Assuming g = 10 m/s^2 )a) 400 N .
b) 520 N.
c) 120 N .
d) 280 N .
Physics Vectors Level: High School
A vector has scalar components of 25 units along the x-axis and 25 square root sign 3 along the y-axis . The magnitude and direction of the vector with respect to positive x-axis is ?a) 25 units and 60* degrees
b) 25 square root sign 3 units and 30*degrees
c) 50 units and 60*degrees
d) 75 units and 45*degrees
Physics Vectors Level: High School
This was from before a person moves 30 cm North then 20 cm East , then 30 square root sign 2 m South-West . His displacement from the original position is ?a) 15m East
b) 28m South
c) 10m West
d) 4m South-west
Physics Vectors Level: High School
If x = a+bt+ct^2 , where x is in meters and t is in seconds , the unit of c is ?a) m
b) s^-2
c) ms^-1
d) ms^-2
Physics Measurements Level: High School
The sides of a rectangle are 6.01 cm and 12 cm . Taking the significant figures into account the area of the rectangle is ?a) 72.00 cm^2
b) 72.1 cm^2
c) 72 cm^2
d) 72.12 cm^2
Physics Measurements Level: High School
The significant figures in 0.080 kg isa) 1
b) 2
c) 3
d) 4
Physics Rotational Mechanics Level: High School
Consider a crane that works by winding the cable around a drum of radius 1.3 m . The motor on the drum causes it to angularly accelerate at .4 rad/sec^2 for 4 seconds before leveling off and maintaining a constant angular velocity . How long does it take to roll in 75 m worth of cable .
Physics Rotational Mechanics Level: High School
Equation of Rotational Motion
A sphere of radius is 40 cm begins angularly accelerating at 5 rad/sec^2 for a period of 7 seconds . At the end of the time what is :a) the angular velocity ?
b) the angular displacement ?
c) the tangential velocity of a point on the edge of rotation
d) the tangential acceleration of a point on the edge of rotation
e) the distance a point on the edge has rotated through .
Physics Electromagnetic Induction Level: High School
Earth’s Magnetism
A 2.5 m blade of a helicopter rotates at 4 rev/s . Find the vertical component of t Earth’s magnetic field if the induced emf between the tip of the blade and the central hub is 3.5 mV .
Physics Electromagnetic Induction Level: High School
The area encircled by the coil , which has 100 turns increases by 19 cm when a baby inhales . The magnitude of B field which makes an angle of 25 degree with the plane of the coil – is 0.00006 T . Assuming that the baby inhales 1.6 s . Find the magnitude of the average emf in the coil during this time .