All categories

3 years ago

A runner can run a 400.0 meter lap in 50.0 seconds. He finishes at the same spot as he began. What is his average velocity?

Physics

2 answers:

cestrela7 [59]3 years ago

8 0

8 meters per second. To find velocity is to divide distance by total time. so 400/50.

Tom [10]3 years ago

5 0

Velocity: displacement/time
as he's back at the same spot, displacement=0
0/50= 0
hope this helps!

You might be interested in

A force of 8,480 N is applied to a cart to accelerate it at a rate of 26.5 m/s2. What is the mass of the cart?

katrin2010 [14]

Answer:

Just use F =ma where m is mass and a is acc.

8 0

3 years ago

An object is released from rest near a planet's surface. A graph of the acceleration as a

Reil [10]

Answer:

The displacement and direction of the body after 2 seconds is 10 meters downwards

Explanation:

The given information are;

From the graph, the acceleration, is seen as the horizontal line that starts from the y-coordinate, y = -5 m/s²

Therefore;

The acceleration of the body after it was released from rest = -5 m/s² with an upward direction;

Which gives, the acceleration of the body downwards = Opposite sign to the acceleration of the body upwards = 5 m/s²

The displacement, s, of the body after 2 seconds is given by the following equation of motion;

s = u·t + 1/2·a·t²

Where;

u = The initial velocity of the body = 0 m/s

t = The time duration of the displacement = 2 s

a = The acceleration of the body = 5 m/s², downwards

Therefore, by substituting the values, we have;

s = 0 × 2 + 1/2 × 5 × 2² = 10 meters

s = 10 meters

The displacement of the body after 2 seconds = 10 meters

Given that the direction of the displacement and the direction of the acceleration are the same, we have;

The displacement and direction of the body after 2 seconds = 10 meters downwards.

7 0

3 years ago

How many kilograms are there in a 2.00 L bottle of drinking water?

nasty-shy [4]

There are 2 kilograms of water in 2 liters of water. if you convert the amount of water to kilograms it equals 2

6 0

3 years ago

Read 2 more answers

A 100 kg person sits on a 5 kg bicycle. The total weight is borne equally by the two wheels of the bicycle. The tires are 2.0 cm

timofeeve [1]

To solve this exercise it is necessary to take into account the concepts related to Pressure depending on the Force and the Area.

The pressure is defined as

$P =\frac{F}{A}$

Where,

$F_w = Force$

$A = Area$

Our values are given as,

$m_1 = 100Kg$

$m_2 = 5Kg$

Where $m_1$ is the mass of the person and $m_2$ is mass of cycle. Therefore the total mass at the system is 105Kg.

For Newton's second law we have:

$F = ma \rightarrow$ where a is the acceleration, in this case the same Gravitational acceleration.

We need to make two considerations, the first is to calculate the total weight and second to calculate the weight on each wheel (2), that is

$F_T = 105*9.8$

$F_T = 1030.05N$

Force in each wheel,

$F_{wheel} = \frac{1030.05}{2}$

$F_{wheel} = 515.025N$

In this way we can now calculate the length based on the pressure, that is

$P = \frac{F_T}{A}$

$P = \frac{F_T}{L*W}$

$L = \frac{F_T}{P*W}$

$L = \frac{515.025}{(8*10^{5})(2*10^{-2})}$

$L = 0.0321m$

Therefore each tire has 3.21cm

8 0

2 years ago

A concrete highway is built of slabs 18.0 m long (at 25 °C). How wide should the expansion cracks be (at 25 °C) between the slab

yulyashka [42]

To solve the problem it is necessary to apply the concepts related to thermal expansion of solids. Thermodynamically the expansion is given by

$\Delta L = L_0 \alpha \Delta T$

Where,

$L_0 =$ Original Length of the bar

$\Delta T$ = Change in temperature

$\alpha$ = Coefficient of thermal expansion

On the other hand our values are given as,

$L_0 = 18m$

$\alpha = 12*10^{-6}/\°C$

$T_2 = 52\°C$

$T_1= 25\°C$

Replacing we have,

$\Delta L = L_0 \alpha (T_2-T_1)$

$\Delta L = (18)(12*10^{-6})(52-25)$

$\Delta L = 5.832*10^{-3}m$

The width of the expansion of the cracks between the slabs is 0.5832cm

7 0

3 years ago