Please help me with this Physics question?

A hockey puck slides off the edge of a horizontal platform with an initial velocity of 20 m/s horizontally and experiences no si

stepladder [879]

Answer:

$v_{yf}=6.26m/s$

Explanation:

We have to focus only on the vertical direction: the puck falls 2m with a null vertical initial velocity. We use the equation:

$v_f^2=v_i^2+2ad$

which for the vertical direction is:

$v_{yf}^2=v_{yi}^2+2a_y\Delta y$

or:

$v_{yf}=\sqrt{v_{yi}^2+2a_y\Delta y}$

Taking the downward direction as positive (which means a positive gravitational acceleration and a positive displaceent) we have for our values:

$v_{yf}=\sqrt{(0m/s)^2+2(9.8m/s^2)(2m)}=6.26m/s$

7 0

3 years ago

You and Mae are in free-float frames. Mae has just passed you, traveling at a speed of 60 km/hr. You throw a ball toward her at

Fantom [35]

She will see the ball as if it were at rest. Relative to her she sees the earth moving back at 60km per hr while the ball moves forward at 60 km per hr. Therefore these velocities will “cancel” in her frame of reference and appear as if the ball were still

7 0

4 years ago

How does a generator convert mechanical energy into electrical energy?

nikdorinn [45]

Answer:

Explanation:

A generator is a device which converts mechanical energy into electrical energy.

It is based on the principle of electromagnetic induction.

The armature coil of the generator rotates by using the mechanical energy. As the armature of the generator rotates, the magnetic flux linked with the coil changes. When the magnetic flux linked with the coil changes, an induced emf is developed.

the magnitude of the induced emf is equal to the rate of change of magnetic flux.

7 0

4 years ago

Describe what happens when u mix hot water with cold

svetoff [14.1K]

The hot immediately increase the temperature of the cold water until they both reach equilibrium state.

6 0

3 years ago

A tuning fork of frequency 254 Hz and an open orang pipe of slightly lower frequency are at 15oC. When

katovenus [111]

The temperature of the air in the open orang pipe has been altered by 18.73° C

The frequency of an open orang pipe is estimated by using the formula:

$\mathbf{f = \dfrac{v}{2L}}$

Then, the combination of the frequency of the tuning fork and the open orang pipe is:

$\mathbf{254 - \dfrac{v}{2L} }$

These combinations of frequency produce 4 beats per sound.

i.e.

$\mathbf{254 - \dfrac{v}{2L} =4}$

$\mathbf{ \dfrac{v}{2L} = 254-4 }$

$\mathbf{ \dfrac{v}{2L} = 250 ----(1)}$

When it is altered, the beats first diminish and increase again by 4.

i.e.

$\mathbf{ \dfrac{v'}{2L} = 254+4 }$

$\mathbf{ \dfrac{v'}{2L} = 258 --- (2) }$

If we equate both equations (1) and (2) together, we have:

$\mathbf{\dfrac{v'}{v}= \dfrac{258}{250}}$

However, from our previous knowledge, we understand that the velocity of an object varies directly proportional to the square root of its temperature.

Hence;