A ball rolling down a hill for 9 seconds accelerates from 3 m/s to 34.5 m/s. What is the ball's rate of acceleration?

Sav [38]

Remote Scottish island

4 0

4 years ago

Show how the alternative definition of power, found in your book, can be derived by substituting the definitions of work and spe

Harman [31]

Let us consider body moves a distance S due to the force F.

Hence the work by the body W = FS

If the force is not along the direction of displacement,then the work by a body for travelling a distance S will be -

$W=[ Fcos\theta]*S$ where $Fcos\theta$ is the component of the force along the direction of displacement.

$Hence\ W= FScos\theta$

$= F.S$

As per the question the power P is given as -

$P=\frac{W}{\delta t}$

$=\frac{F.S}{\delta t}$

$= F.\frac{S}{\delta t}$

$= \ F.V$

Hence alternative definition of power P = F.V

8 0

3 years ago

Read 2 more answers

Three basic electrical effects occur when an electric current flows in a conductor: A magnetic field is set up around the conduc

Alex787 [66]

Answer:

A drop in voltage occurs

Explanation:

When electric current flows through a conduct, there are three basic electrical effects that occur to the conductor;

1. A magnetic field is set up around the conductor,

A magnetic field is formed around a conductor when current flows through it which makes it acts like a magnet. Application is used in electric bells.

2. Heat is generated, and

The heating effect of current is due to the conversion of some of the electrical energy that passes through the conductor, into heat energy. Application of heat effect include electric iron, microwave oven, electric bulb, hair straightener etc.

H = I²Rt

3. A drop in voltage occurs

Voltage drop is as a result of current passing through the impedance offers by the conductor or circuit elements. When current passes through a conductor, the resistance offers opposition to the flow of the electric current according to Ohm's law.

7 0

3 years ago

A man stands by a train track to watch the train car go by. Inside, a man walks through the train car eating a hot dog (the hot

antiseptic1488 [7]

Answer:

D) 11 m/s

Explanation:

The problem asks us to calculate the velocity of the hot dog with respect to the observer stationary outside the train. This velocity is given by:

$v=v_t + v_m + v_h$