Physics Problem Grade 12

Physics Problem, Grade 12?

I'm assuming you meant radial velocity. There is not enough information given to find the radial acceleration.

Recall that an object in constant circular motion is an object constantly being accelerated centripetally. At all points of time, the object is attempting to travel at a velocity v, tangentially to the path of circular motion. This tangential velocity can also be referred to as the radial velocity.

If the ball lands 2.05 m away from the initial position of the ball after the string breaks, that means

2.05m = (tangential velocity)(t seconds)

To find t, we know that 1.07m = 0.5(9.8m/s^2)(t^2)
t^2 = 0.218 s
t = 0.467 s

2.05m = (v)(0.467s)
v = 4.39 m/s

Radial acceleration of an object related to its tangential velocity is a_r = v^2 /r, in this case:

(4.39)^2 / (0.305) = 63.19 m/s^2

(oops, confused translational acceleration with radial acceleration)

Physics problem grade 12?

In certain fire extinguishers, carbon dioxide gas is pressurized until it liquifies. When the pressure is released, the liquid carbon dioxide vaporizes and shoots out of the extinguisher. The area on which it is applied experiences a rapid lowering of temperature due to the cold temperature of the gas and the constant stream of gas blowing heat off the applied surface. (Additionally, fires die without oxygen, O2, so the application of CO2 pushes oxygen away from the burning surface. This isn't related to the question, though ...) Most of the released carbon dioxide gas escapes into the atmosphere, but the extreme cold causes some of the gas to compress and solidify into small pellets of dry ice.

Grade 12 Physics Problems?

Draw a diagram to show velocities/directions before and after the collision (guess the can's direction).

u and v indicate initial and final velocities,
u₁’s direction is taken as +x (horizontal to the right)
u₂’s direction is taken as +y (vertically upwards)
α is assumed 70° anticlockwise relative to the +x direction (i.e. diagonally upwards).

Make sure you know how to resolve a vector into components. And how to add perpendicular vectors to get the resultant’s magnitude and direction. If you don’t, try the videos in the links.

Momentum is conserved in x direction.
initial x-momentum = final x-momentum
m₁u₁ₓ + m₂u₂ₓ = m₁v₁ₓ + m₂v₂ₓ
0.78*7.6 + 1.3*0 = 0.78*6.1cos(70°) + 1.3v₂ₓ
v₂ₓ = (0.78*7.6 – 0.78*6.1cos(70°))/1.3
. . . = 3.308m/s

Momentum is conserved in y direction.
initial y-momentum = final y-momentum
m₁u₁ᵧ + m₂u₂ᵧ = m₁v₁ᵧ + m₂v₂ᵧ
0.78*0 + 1.3*5 = 0.78*6.1sin(70°) + 1.3v₂ᵧ
v₂ᵧ = (1.3*5 – 0.78*6.1sin(70°))/1.3
. . . = 1.561m/s

The angle of m₂ (the can) relative to +x direction is θ, given by:
tanθ = v₂ᵧ/v₂ₓ
θ = tan⁻¹(1.561/3.308) = 25°

Can’s speed is the magnitude of the vector sum of its velocity components:
v₂ = √(v₂ₓ² + v₂ᵧ²) = √(3.308 ² + 1.561²) = 3.7m/s to 2 sig. figs.

Obviously check my working/arithmetic.

Help! Grade 12 Physics problem?

3) (a) By the law of energy conservation:-
=>PE(initial) of the (spring+object) = KE(final) of the object + PE(final) of the spring
Let the PE of the object is zero as the compressed position(i.e refrence point).
=>1/2kx^2 = mgx + 1/2mv^2
=>1/2 x 500 x (0.05)^2 = 20 x 10^-3 x 9.8 x 0.05 + 1/2 x 20 x 10^-3 x v^2
=>v = √61.52
=>v = 7.84 m/s
(b) By the law of energy conservation:-
=>PE(initial) of the spring = PE(final) of the ball
=>1/2kx^2 = mgh
=>h = kx^2/2mg
=>h = [500 x (0.05)^2]/[2 x 20 x 10^-3 x 9.8]
=>h = 3.19 m

Grade 12 Physics Problem - Dynamics?

Slack lining is doing tricks while standing on a rope stretched between two trees as shown in the photo. A 60 kg person standing in the middle of a 5.0m rope causes it to go down 50 cm. Calculate the tension in the rope.

Grade 12 Physics Problem.. Any help will be greatly appreciated :)?

By F(net) = F(gravity) - F(friction)
=>m x a = mgsinA* [as Ff = 0,given]
=>a = 9.8 x sinA*
=>1.5 = 9.8sinA*
=>sinA* = 1.5/9.8 = 0.153 = sin8.8*
=>A = 8.8*
F(gravity)= mg, will be acting vertically but on a slope the component of it parallel to the slope i.e. in the direction of motion needed to be counted by multiplying mg by sinA*.

Help with this Grade 12 Physics problem?

2. Shuffleboard is a game where disks are slid to the end of a long board and bounce off each other. Two shuffleboard disks of equal mass (one orange, one yellow) are involved in a perfectly elastic, glancing collision. The yellow disk is initially at rest and is struck by the orange disk moving with a speed of 5.00 m/s. After the collision the orange disk moves along a direction that makes an angle of 37.0o with its initial direction of motion and the velocity of the yellow disk is perpendicular to that of the orange disk (after the collision). Determine the final speed of each disk.

Tough Grade 12 Physics Test Questions?

I specifically remember that question (i.e, drill a hole through the center of the Earth, throw a pebble in, what is its subsequent motion) as a homework question I got while I was a freshman in college. Here is an outline of the solution: Gravitational potential goes as M r^-1, where M is the mass of the Earth below you. M is now a function of radius as well, specifically, it is proportional to the volume of a sphere, which goes as r^3. Combined together, you have an effective potential that goes as r^2. You should recognize that r^2 corresponds to a harmonic oscillator potential, hence your motion will be sinusoidal with constant frequency.

While you could reason out a qualitative answer, I agree that a quantitative answer is probably beyond the level of most high school physics curricula. I'm not a big fan of multiple choice tests, especially when it is physics, but your teacher may think differently.

For more questions that are on that level of difficulty, I would suggest checking out some freshman level physics textbooks. For instance, the one I used was "An Introduction To Mechanics" by Kleppner and Kolenkow.

I am not aware of any good online sources. If you can find practice questions for the International Physics Olympiad, those are good question sources

http://www.aapt.org/physicsteam/exams.cf...