when an object is moving there is always a force pulling it in the direction of its motion?true or false? explain

A 1000-kilogram truck accelerates uniformly from rest, reaching a speed of 50 meters per second in 10 seconds. During the 10 sec

Nata [24]

Answer:

250 m

Explanation:

1. First, we have to calculate the acceleration:

$\boxed{\mathsf{v=v_o+a\cdot t}}$

where:

v = present velocity

vo = initial velocity

a = acceleration

t = time

2. Let us use given information and substitute in the expression above. Hence:

$\mathsf{50=0+a\cdot10}\\\\\mathsf{50=10\cdot a}\\\\\mathsf{a=\dfrac{50}{10}}\\\\\therefore \boxed{\mathsf{a=5\,m/s^2}}}$

3. Now we can calculate traveled distance with <u>Torricelli's equation</u>:

$\boxed{\mathsf{v^2=v_o^2+2\cdot a \cdot d}}$

where:

v = present velocity

vo = initial velocity

a = accelerarion

d = distance

4. So, we get:

$\mathsf{50^2=0^2+2\cdot 5 \cdot d}\\\\\mathsf{2500=10\cdot d}\\\\\mathsf{d=\dfrac{2500}{10}}\\\\\therefore \boxed{\mathsf{d=250\,m}}$

<u>Conclusion</u>: during 10 seconds the truck has traveled a distance of 250 m.

Have a nice day! : )

8 0

3 years ago

A bird is flying in a room with a velocity field of . Calculate the temperature change that the bird feels after 9 seconds of fl

Korvikt [17]

Complete Question

The complete question is shown on the first uploaded image

Answer:

The temperature change is $\frac{dT}{dt} = 1.016 ^oC/m$

Explanation:

From the question we are told that

The velocity field with which the bird is flying is $\vec V = (u, v, w)= 0.6x + 0.2t - 1.4 \ m/s$

The temperature of the room is $T(x, y, u) = 400 -0.4y -0.6z-0.2(5 - x)^2 \ ^o C$

The time considered is t = 10 \ seconds

The distance that the bird flew is x = 1 m

Given that the bird is inside the room then the temperature of the room is equal to the temperature of the bird

Generally the change in the bird temperature with time is mathematically represented as

$\frac{dT}{dt} = -0.4 \frac{dy}{dt} -0.6\frac{dz}{dt} -0.2[2 * (5-x)] [-\frac{dx}{dt} ]$

Here the negative sign in $\frac{dx}{dt}$ is because of the negative sign that is attached to x in the equation

So

$\frac{dT}{dt} = -0.4v_y -0.6v_z -0.2[2 * (5-x)][ -v_x]$

From the given equation of velocity field

$v_x = 0.6x$

$v_y = 0.2t$

$v_z = -1.4$

So

$\frac{dT}{dt} = -0.4[0.2t] -0.6[-1.4] -0.2[2 * (5-x)][ -[0.6x]]$

substituting the given values of x and t

$\frac{dT}{dt} = -0.4[0.2(10)] -0.6[-1.4] -0.2[2 * (5-1)][ -[0.61]]$

$\frac{dT}{dt} = -0.8 +0.84 + 0.976$

$\frac{dT}{dt} = 1.016 ^oC/m$

5 0

3 years ago

The master gland of the endocrine system is the: (2 points)

galben [10]

Answer: Pituitary Gland

Explanation: The pituitary gland produces hormones that control other glands and body functions, therefore, it is sometimes called the master endocrine gland.

8 0

4 years ago

Read 2 more answers

an empty bottle has a mass of 24,25 grams and 86,55 grams completely full-filled with water. Then, water in the bottle is emptie

ladessa [460]

The density of a substance is the quotient we obtain when we divide its mass by the volume. The density is,
density = mass / volume
The mass of carbon tetrachloride is given to be 123.95 grams and that the volume is obtained by subtracting final weight of the completely full-filled with water bottle with the initial weight.
86.55 - 24.25 = 62.3 grams
Since the density of water is 1 grams/ cc. Then, the volume of the bottle is also 62.3 cc. The density is therefore,
density = 123.95 grams/ 62.3 cc = 1.99 g/cc

4 0

3 years ago

Two bicycle tires are set rolling with the same initial speed of 4.00 m/s along a long, straight road, and the distance each tra

77julia77 [94]

Answer:

The coefficient of rolling friction for the tire under low pressure is 0.0342.

Explanation:

Two bicycle tires are set rolling with the same initial speed of 4.00 m/s

Final speed of both the bicycle, speed is reduced by half is measured, v = 2 m/s.

Here,

$u_kmg = ma\\\\a=\mu g$

Using third equation of motion as :

$v^2-u^2=2as\\\\v^2-u^2=2\mu gs\\\\\mu =\dfrac{v^2-u^2}{2gs}\\\\\mu =\dfrac{4^2-2^2}{2\times 9.8\times 17.9}\\\\\mu=0.0342$

So, the coefficient of rolling friction for the tire under low pressure is 0.0342.

5 0

3 years ago