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2 years ago

A body of mass 20kg initially at rest is subjected to a force of 40m for 15sec. Calculate the change in k.e

Physics

2 answers:

Ede4ka [16]2 years ago

3 0

Explanation:

mass(m)=20kg

velocity(v)=d/t=2.67

k.e=?

now,

k.e=1/2mv^2

=1/2*20*(2.67)^2

=71J

vladimir2022 [97]2 years ago

3 0

Answer:

Explanation:kE =10kg(7.3m²/s²)

=73J

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What best describes desert pavements

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Explanation:

A common theory suggests that desert pavements are formed through gradual removal of sand and other fine particles by the wind and intermittent rains leaving behind the large fragments. The larger rock particles are shaken into place by actions of different agents such as rain, wind, gravity, and animals

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4 years ago

Why is random sampling and random assignment in experimental research important?

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So the result is not biased or affected in some way

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3 years ago

At this rate, how long would it take for two continents 3500 kilometers apart to collide?

meriva

Given:

3,500 kilometers

Find:

Years for two continents to collide = ?

Solution:

We know that typical motions of one plate relative to another are 1 centimeter per year.

So first, we convert 3,500 km to cm.

The solution would be like this for this specific problem:

1 km = 100,000 cm

3,500 km x 100,000 = 350,000,000 cm

Since we know that 1 cm = 1 year, then that means 350,000,000 cm is equivalent to 350,000,000 years.

Therefore, it would take 350 million years for two continents that are 3500 kilometers apart to collide.

To add, a phenomenon of the plate tectonics of Earth that occurs at convergent boundaries is called the continental collision.

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3 years ago

A 86 kg human stands on the surface of Venus. The mass of Venus is 4.9 × 1024 kg and its radius is 6.1 × 106 m. Collapse questio

iris [78.8K]

Answer:

755.37 N

Explanation:

We are given that

Mass of venus= $m_1=4.9\times 10^{24}kg$

Radius= $r=6.1\times 10^6$ m

Mass of human= $m_2=86 kg$

We know that the gravitational force between two bodies

$F=G\frac{m_1m_2}{r^2}$

Where G=Gravitational constant= $6.67\times 10^{-11}Nm^2/kg^2$

Using the formula

The magnitude of the gravitational force exerted by Venus on the human= $F=\frac{6.67\times 10^{-11}\times 86\times 4.9\times 10^{24}}{(6.1\times 10^6)^2}$

The magnitude of the gravitational force exerted by Venus on the human=F= $755.37N$

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3 years ago

The force of air resistance acts to oppose the motion of an object moving through the air. A ball is thrown upward and eventuall

ozzi

Answer:

For a (1) net force will be greater than the weight of the ball

For b (2) net force will be lesser than the weight of the ball

Explanation:

For (a):

For a linear motion of a system, one must have to understand, according to Newtons first law of motion, which is also known as law of inertia, a body which is at motion will continue to move or a body at rest will continue to rest until an external force is applied to it. In the given case, when ball goes upward, one thing is for sure, the net force is greater than the weight of the ball, because three forces are applied during upward motion:

gravity or weight which is pulling the ball downward,

air resistance, which is also acting downward as it is creating friction between ball and air molecules, so creating hindrance in upward motion

External force to throw ball upward

Net Force = Upward force - Air friction - Weight

Since ball is going upward, so net force is greater than both weight and air friction which are pulling ball downward.

For (b):

For a linear motion of a system, one must have to understand, according to Newtons first law of motion, which is also known as law of inertia, a body which is at motion will continue to move or a body at rest will continue to rest until an external force is applied to it. In the given case, when ball goes downward, one thing is for sure, the net force is lesser than the weight of the ball, because two forces are applied during downward motion:

gravity or weight which is pulling the ball downward,

air resistance, which is acting upward as it is creating friction between ball and air molecules, so creating hindrance in downward motion

Net Force = Weight - Air friction

Since ball is going downward, so weight is greater than net force which is in this case is air friction which is pulling ball upward.

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4 years ago