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3 years ago

Often in Physics we will show a frame of reference as a

Physics

1 answer:

OlgaM077 [116]3 years ago

8 0

Answer:

In physics, a frame of reference, or reference frame, is a perspective that one uses to determine if an object is moving.

Explanation:

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acceleration is defined as the rate of change for which characteristic? a. displacement b. position c. velocity d. time

fredd [130]

The answer is velocity.

7 0

3 years ago

How much electrical energy is used by the river cooker oven rated 800 W ,230 V is switched on for 30 minutes

mariarad [96]

Answer:

E = 1440 kJ

Explanation:

It is given that,

Power of a cooker oven is 800 W

Voltage at which it is operated is 230 V

Time, t = 30 minutes = 1800 seconds

We need to find the electrical energy used by the cooker oven. The product of power and time is equal to the energy consumed. So,

$E=P\times t\\\\E=800\ W\times 1800\ s\\\\E=1440000\ J\\\\\text{or}\\\\E=1440\ kJ$

So, electrical energy of 1440 kJ is consumed by the cooker oven.

8 0

3 years ago

The picture below shows a football player kicking a football. This is known as two dimensional motion. In which direction does t

Molodets [167]

You are true, Stokey. The correct choice is<em> (c)</em>.

If you think about it a little bit more, you'll realize that "side to side" is also a horizontal motion.

Anyway, the question told us that we're only talking about 2 dimensions. Well, the The measurements in the 2 dimensions are the x and the y . If there were a z measurement, that would be the 3rd dimension.

7 0

2 years ago

Light of frequency 2.5 x 1015 Hz illuminates a

Nikitich [7]

Answer:

h f = W + KE

Input energy equals work function plus KE of emitted electron

W = 6.63E-34 * 2.5E15 - 6.3 * 1.6E-19

W = 6.63 * 2.5 * 10^-19 - 10.1 * E-19 ev (1ev = 1.6E-19 J)

W = (16.6 - 10.1)E-19 = 6.5E-19 J

h f = 6.5E-19 J for electrons to be emitted with zero KE

f = 6.5E-19 / 6.63E-34 = .98E-15 / sec = 9.8E-14 / sec (threshold)

3 0

2 years ago

A rock falls from rest off a cliff and hits the ground in 2 seconds. If there is no air resistance, determine the rock's velocit

mihalych1998 [28]

Answer:

19.6m/s

Explanation:

A Rock falling off a cliff can be modeled as an object starting with zero velocity moves with constant acceleration for certain period of time, for such motion following equation of motion can be used.

$v(t) = v_{0} +at$

here in our case $v_{0} =0$ because object starts off from rest and $a = g =9.8m/s^2$ is acceleration because of gravity ( Motion under gravity).

and of course t = 2 second.

Now by substituting all this information in equation of motion we get.

$v(2s) = 0+9.8m/s^2 *2s = 19.6m/s$

that would be the velocity of rock as it would hit the ground.

Note! We have assumed that there is no air resistance.

A rock falling off a cliff can be modeled as an object starting with zero velocity moves with constant acceleration for a certain period of time, for such motion following equation of motion can be used.

here in our case because object starts off from rest and is acceleration because of gravity ( Motion under gravity).

and of course t = 2 seconds.

Now by substituting all this information in equation of motion we get.

V = 19.6m/s

that would be the velocity of rock as it would hit the ground.

Note! We have assumed that there is no air resistance.

5 0

2 years ago