What three ways are molecules used when they are stored for energy?

How much work must be done on a 5 kg snowboard to increase its speed from 2 m/s to 4 m/s

Zielflug [23.3K]

Answer:

a) 30J

Explanation:

use formula first find K.E with both speeds

K.E. = 1/2 m v2

and then

work done= change in kinetic energy

8 0

3 years ago

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A person in a kayak starts paddling, and it accelerates from 0 to 0.65 m/s in a distance of 0.40 m. If the combined mass of the

SCORPION-xisa [38]

Answer:

Magnitude of the net force acting on the kayak = 39.61 N

Explanation:

Considering motion of kayak:-

Initial velocity, u = 0 m/s

Distance , s = 0.40 m

Final velocity, v = 0.65 m/s

We have equation of motion v² = u² + 2as

Substituting

v² = u² + 2as

0.65² = 0² + 2 x a x 0.4

a = 0.53 m/s²

We have force, F = ma

Mass, m = 75 kg

F = ma = 75 x 0.53 = 39.61 N

Magnitude of the net force acting on the kayak = 39.61 N

6 0

3 years ago

**

lys-0071 [83]

Answer:

The object will have an upward acceleration

Explanation:

Let's consider the forces applied on the box. We have only two forces:

- The applied force of push, $F_p$ , downward

- The force of gravity, $W$ , (also known as weight of the object), downward

Therefore, the net force on the box is:

$F_{net}=F_p -W$

Here, we know that force applied is equal or greater than the weight, so

$F_p \geq W$

And therefore the net force is greater than zero:

$F_{net}\geq 0$ (1)

According to Newton's second law of motion, the net force on the box is equal to the product between its mass and its acceleration:

$F_{net}=ma$

where

m is the mass of the box

a is its acceleration

Given (1), this means that

$a\geq 0$

Therefore, the box will have an upward acceleration.

In this case force example we have:

$F_p = 100 N\\W = 40 N$

So the mass of the box is

$m=\frac{W}{g}=\frac{40}{10}=4 kg$

So the net force is

$F_{net}=F_p-W=100-40=60 N$

And the acceleration is

$a=\frac{F_{net}}{m}=\frac{60}{4}=15 m/s^2$

4 0

3 years ago

Differentiate gravitational force and acceleration due to gravity

julia-pushkina [17]

Answer:

I hope this answer is correct

Explanation:

Difference Between Gravitation and Gravity

Gravitation is referred to the force acting between two bodies which can be represented as the F=(GM1M2)/R2 which means gravitation force is proportional to the product of the masses of the object 1 and object 2 and is inversely proportional to the square of the distance between them. The gravitational force between earth and any object is known as gravity.

Difference Between Gravitation and Gravity

Gravitation Gravity

It is a universal force It is not a universal force

It is a weak force It is a strong force

The force is F=(GM1M2)/R2 (G= gravitational constant) The force is F=mg (g=acceleration due to gravity)

The direction of gravitational force lies in the radial direction from the masses The direction of the force of gravity is along the line joining the earth’s center and the center of the body. Its direction is towards the center of the earth.

The force can be 0 when the separation between bodies is infinity The force of gravity can be 0 at the center of the earth

It requires two masses It requires only one mass

These were some difference between Gravitation and Gravity. If you wish to find out more, download BYJU’S The Learning App.