All categories

3 years ago

What is instantaneous speed

1 answer:

5 0

What is instaneous speed? When the speed of an object is constantly changing, the instantaneous speed is the speed of an object at a particular

You might be interested in

A 22.0 kg child slides down a slide that makes a 37.0° angle with the horizontal. (a) What is the magnitude of the normal force

patriot [66]

Answer:

(a) 172.185 N

(b) $53^{\circ}$

Solution:

As per the question:

Mass of the child, m = 22.0 kg

Angle, $\theta = 37.0^{\circ}$

Now,

(a) The magnitude of the normal force exerted by the slide on the child:

$F_{N} = mgcos\theta$

$F_{N} = 22\times 9.8cos37^{\circ} = 172.185\ N$

Now,

(b) The angle from the horizontal at which the force is directed is:

$90^{\circ} - 37^{\circ} = 53^{\circ}$

6 0

3 years ago

A car initially at rest accelerates at 10m/s^2. The car’s speed after it has traveled 25 meters is most nearly... A.) 0.0m/s B.)

STALIN [3.7K]

The car traverses a distance $x$ after time $t$ according to

$x=\dfrac12at^2$

where $a$ is its acceleration, 10 m/s^2. The time it takes for the car to travel 25 m is

$25\,\mathrm m=\left(5\dfrac{\rm m}{\mathrm s^2}\right)t^2\implies t=\sqrt 5\,\mathrm s$

5 is pretty close to 4, so we can approximate the square root of 5 by 2. Then the car's velocity $v$ after 2 s of travel is given by

$v=\left(10\dfrac{\rm m}{\mathrm s^2}\right)(2\,\mathrm s)\approx20\dfrac{\rm m}{\rm s}$

which makes C the most likely answer.

3 0

3 years ago

6. Two light bulbs are designed for use at 120 V and are rated at 75 W and 150 W. Which light bulb has the greater filament resi

Nonamiya [84]

$\\ \bull\tt\longrightarrow P=\dfrac{V^2}{R}$

P is power
R is resistance

$\\ \bull\tt\longrightarrow R=\dfrac{V^2}{P}$

Hence

$\\ \bull\tt\longrightarrow R\propto V$

$\\ \bull\tt\longrightarrow R\propto \dfrac{1}{P}$

Therefore if power is low then resistance will be high.

The first bulb has less power hence it has greater filament resistance.

5 0

3 years ago

Can you please give me the answers ?

rodikova [14]

Answer:

237

Explanation:

7 0

3 years ago

A ball of mass 2 kg is kept on the hill of height 3 km. Calculate the potential energy possessed by it ?

zysi [14]

We know that -

$P.E=m*g*h$

Where,

$m = mass$

$g = acceleration$ $due$ $to$ $gravity$

$h=height$

First we convert height into meters.

1 km = 1000 meters

3 km = 1000 * 3 meters = 3000 meters

So, putting the values in the above formula, and by taking 'g' = 9.8 m/s², we get-

$P.E.= 2*3000*9.8$

$P.E.= 58800$ $Joules$

$P.E.= 58.8$ $kJ$

7 0

3 years ago

Read 2 more answers