Answer:
a) 5.61 rad/s
b) 16.83 rad/s
Explanation:
Distance to the floor = 79cm = 0.79m
Rotation is <1 revolution
The toast will rotate at an angular speed that is constant while it falls. The toast will also be falling with constant acceleration due to gravity. Using equation of motion, which is
S = ut + 1/2gt²
S = 0 + 1/2gt²
S = gt², where, S = d
0.79 = 9.81t²
t² = 0.79/9.81
t² = 0.081
t = 0.28s
As the toast is accidentally pushed, it rotates as it falls. It will be landing on its edges when and if it hits the ground. The smallest angle here would then be 1/4 of the revolution. This is also the smallest angular speed.
ω(min) = ΔΦ revolution /Δt
ω(min) = 1/4 * 2π / 0.28
ω(min) = 0.5π/0.28
ω(min) = 5.61 rad/s
Since 1/4 of revolution is the minimum angle, the remaining(3/4), is the maximum angle. Thus
ω(max) = 3/4 * 2π / 0.28
ω(max) = 0.75 * 2π / 0.28
ω(max) = 16.83 rad/s
The image formed by a concave mirror with the object placed at the center of curvature is real inverted and formed at the center of curvature. Using the ray diagram a ray from the top of the object to the mirror through f then reflected parallel to the principal axis,then the ray through the center of curvature reflected through the same point both intersect at a plane through center curvature and perpendicular to the principal axis. The point of intersection forms the top of the image and the center of curvature forms the bottom. Therefore, the correct choices are : real and inverted
Refer to the diagram shown.
There are twelve 5-minute divisions.
Each 5-minute division is equal to 360°/12 = 30°.
By convention, angles are measured counterclockwise from the positive x-axis.
The angular position of the minute hand at 2:55 is
θ = 90° + 30° = 120°
Because 360° = 2π radians, therefore
θ = (120/360)*2π = (2π)/3 radians = 2.0944 radians
Answer: (2π)/3 radians ofr 2.0944 radians.
Answer:
False
Explanation:
The steel ball and the wooden ball do not have the same force acting on them because their masses are different. But, they have the same acceleration which is the acceleration due to gravity g = 9.8 m/s².
Using the equation of motion under freefall, s = ut +1/2gt². Since u = 0,
s = 1/2gt² ⇒ t = √(2s/g)
Since. s = height is the same for both objects, they land at the same time neglecting air resistance.