All categories

3 years ago

Use the graph above to determine the change in speed of the object between 20 and 30 seconds?

Physics

2 answers:

allsm [11]3 years ago

4 0

Answer:

6 m/s

Explanation:

To determine the change in speed of the object, we just need to determine its speed at t = 30 s and at t = 20 s, and then calculate the difference.

The speed at t = 30 is:

v = 6 m/s

While the speed at t = 20 s is:

u = 0

Therefore, the change in speed is:

$\Delta v = v-u=6-0 = 6 m/s$

lara31 [8.8K]3 years ago

4 0

Explanation:

The attached figure shows the acceleration time graph of an object. We known that the slope of the a-t graph gives the velocity of an object. The area under the a-t graph gives the velocity of object.

In x axis, time t = 30 s- 20 s = 10 s

In y axis, acceleration, $a = 6 - 0=6\ m/s^2$

Area under the graph from 20 to 30 seconds is given by :

$A=v=\dfrac{1}{2}\times 10\times 6$

v = 30 m/s

So, the change in speed of the object is 30 m/s. Hence, this is the required solution.

You might be interested in

A small sphere has a harge of 9uC and other small sphere has a charge of 4uC.

Helga [31]

Answer:

Electrical force, F = 90 N

Explanation:

It is given that,

Charge on sphere 1, $q_1=9\ \mu C=9\times 10^{-6}\ C$

Charge on sphere 2, $q_1=4\ \mu C=4\times 10^{-6}\ C$

Distance between two spheres, d = 6 cm = 0.06 m

Let F is the electrical force between them. It is given by the formula of electric force which is directly proportional to the product of charges and inversely proportional to the square of distance between them such that,

$F=k\dfrac{q_1q_2}{d^2}$

$F=9\times 10^9\times \dfrac{9\times 10^{-6}\times 4\times 10^{-6}}{(0.06)^2}$

F = 90 N

So, the electrical force between them is 90 N. Hence, this is the required solution.

7 0

3 years ago

An automobile engine delivers 55.0 hp. How much time will it take for the engine to do 6.22 × 105 J of work? One horsepower is e

Gennadij [26K]

Answer:

15.2 s

Explanation:

Convert hp to W:

55.0 hp × 746 W/hp = 41,030 W

Power = energy / time

41030 W = 6.22×10⁵ J / t

t = 15.2 s

8 0

3 years ago

It is friction that provides the force for a car to accelerate, so for high-performance cars the factor that limits acceleration

bearhunter [10]

Answer:

About 12 seconds

Explanation:

6 0

3 years ago

Part a consider a bird that flies at an average speed of 10.7 m/s and releases energy from its body fat reserves at an average r

Alex787 [66]

<span>436 km The conversion factor between kilocalorie/hour and watts is 1.163 (1 kcal/hr = 1.163 watt). So let's convert the energy consumption of the bird from watts to kcal/hr 3.7 w / 1.163 w hr/kcal = 3.18 kcal /hr 1 gram of fat has 9 kcal, so the total number of kcals consumed will be 4 * 9 = 36. So the bird can fly for 36/3.18 = 11.32 hours The distance traveled will be 11.32 h * 3600 s/h * 10.7 m/s / 1000 m/km = 436 km</span>

5 0

3 years ago

Whenever you push an object across a frictional surface, it starts out taking a lot of force to push to get the object moving. H

son4ous [18]

Answer:

The answer is A

Explanation:

Here's an example. A child is in school taking a test. They have made a mistake on a question, and want to erase it. The eraser is made out of a type of rubber, the rubber has friction, which means the eraser has something that's going to resist movement. Now the child has exerted enough force to get it moving, and it's moving, it won't stop unless the child stops exerting force to keep it moving. Both Newton's 1st and 3rd law explain the action of moving something on a surface with friction.

5 0

3 years ago