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3 years ago

How does a bicycle rider's energy of motion changes as the gain speed while riding down a hill?

1 answer:

8 0

It is b. It gains momentum when going down. Think of it like a sled. When you go up the hill, it goes slower, but when you go down the hill, you gain speed(momentum) and it increases

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Which temperature is warmer than the freezing point of water

worty [1.4K]

Answer:

1°C

Explanation:

Water freezes at 0°C, 32°F, and 273°K.

The only temperature warmer than the freezing point is 1°C.

7 0

3 years ago

An air balloon is moving upward at a constant speed of 3 m/s. Suddenly a passenger realizes that she left her camera on the grou

frosja888 [35]

Answer:t=0.3253 s

Explanation:

Given

speed of balloon is $u=3\ m/s$

speed of camera $u_1=20\ m/s$

Initial separation between camera and balloon is $d_o=5\ m$

Suppose after t sec of throw camera reach balloon then,

distance travel by balloon is

$s=ut$

$s=3\times t$

and distance travel by camera to reach balloon is

$s_1=ut+\frac{1}{2}at^2$

$s_1=20\times t-\frac{1}{2}gt^2$

Now

$\Rightarrow s_1=5+s$

$\Rightarrow 20\times t-\frac{1}{2}gt^2 =5+3t$

$\Rightarrow 5t^2-17t+5=0$

$\Rightarrow t=\dfrac{17\pm \sqrt{17^2-4(5)(5)}}{2\times 5}$

$\Rightarrow t=\dfrac{17\pm 13.747}{10}$

$\Rightarrow t=0.3253\ s\ \text{and}\ t=3.07\ s$

There are two times when camera reaches the same level as balloon and the smaller time is associated with with the first one .

(b)When passenger catches the camera time is $t=0.3253\ s$

velocity is given by

$v=u+at$

$v=20-10\times 0.3253$

$v=16.747\ m/s$

and position of camera is same as of balloon so

Position is $=5+3\times 0.3253$

$=5.975\approx 6\ m$

8 0

3 years ago

A runner completes the 200-meter dash with a time of 19.80 seconds. What was the runner's average speed in miles per hour?

andriy [413]

Answer:

v = 22.54 mph.

Explanation:

Given that,

Distance moved, d = 200 m

Time, t = 19.8 s

We need to find the runner's average speed.

We know that,

1 mile = 1609.34 m

200 m = 0.124 miles

19.8 seconds = 0.0055 h

So,

Speed = distance/time

$v=\dfrac{0.124}{0.0055}\\\\v=22.54\ mph$

So, the runner's average speed is 22.54 mph.

4 0

3 years ago

Which element is most likely to carry electric current easily?

Sindrei [870]

The most likely element is silver
in second place is copper

3 0

4 years ago

A simple pendulum has length of 820mm. Calculate the frequency (g = 9.8 ms -2)

Vadim26 [7]

Answer:

$\huge\boxed{\sf f=0.55 \ Hz}$

Explanation:

Given Data:

Length = l = 820 mm = 0.82 m

Acceleration due to gravity = g = 9.8 ms⁻²

Required:

Frequency = f = ?

Formula:

$\displaystyle f =\frac{1}{2 \pi} \sqrt{\frac{g}{l} }$

Solution:

$\displaystyle f =\frac{1}{2 \pi} \sqrt{\frac{g}{l} } \\\\Put\ the\ givens\\\\f=\frac{1}{2 \pi} \sqrt{\frac{9.8}{0.82} }\\\\ f = 0.159 \times \sqrt{11.95} \\\\f=0.159 \times 3.457\\\\f=0.55 \ Hz\\\\\rule[225]{225}{2}$

7 0

2 years ago