All categories

2 years ago

A runner of mass 80 kg is moving at 8.0 m/s. Calculate her kinetic energy.

Physics

1 answer:

lana [24]2 years ago

7 0

Answer:

2560J

Explanation:

By definition the kinetic energy can be calculated in the following way:

K = (mv²)/2 = 80kg·(8.0m/s)²/2 = 2560 J

You might be interested in

Two charged bees land simultaneously on flowers that are separated by a finite distance. For a few moments, the charged bees res

damaskus [11]

Answer:

Same, the electric fields point in opposite directions and therefore cancel at some midpoint.

Explanation:

The Electric field net at some point between them is zero, only if they point in opposite direction (they cancel to the each other). In order the electric fields have opposite direction, at some point between the bees , the bees must have the same sign of electric charge

3 0

4 years ago

Two force vectors are oriented such that the angle between their directions is 38 degrees and they have the same magnitude. If t

Usimov [2.4K]

Answer:

Sum of the forces will be equal to 3.479 N

Explanation:

We have given two same forces are oriented at an angle of 38°

Magnitude of each force is given $F_1=F_2=1.84$

We have to find the sum of the forces

Sum of the forces will be equal to

$F=\sqrt{F_1^2+F_2^2+2F_1F_2cos\Theta }$

So sum of the forces will be equal to $F=\sqrt{1.84^2+1.84^2+2\times 1.84\times 1.84\times cos38^{\circ} }=3.479$

So sum of the force will be equal to 3.479 N

6 0

3 years ago

This is one of the four planets Mercury,Venus,Earth,and Mars, whose orbits lie nearest the Sun

galben [10]

Answer:

Mercury

Explanation:

Mercury is the closest planet to the sun followed be Venus. Though Mercury is the closest Venus is actually the hotest planet

6 0

3 years ago

Read 2 more answers

vector u has a magnitude of 20 and direction of 0°.vector v has amagnitude of 40and a direction of 60°.find the magnitude and di

pantera1 [17]

Addition of vectors:

vector u

has a magnitude of 20 and a direction of 0º with respect to the horizontal, vector v has a magnitude of 40 and a direction of 60º with respect to the horizontal.

a) Find the magnitude and direction of the resultant to the nearest whole

number.

Vector Sum:

The resultant of two vectors is simply the vector sum of the vectors. There are a handful of ways to present the resultant factor; the notation that shows the vector magnitude and direction is called the polar vector notation. An example of a vector presented in polar vector notation is

a∠θ where a is the magnitude and θis the angle that the vector makes with the horizontal axis.

Answer and Explanation:

Let's first present the vectors in rectangular vector notation.

For the vector →u of magnitude 20 and direction 0∘ to the horizontal axis, the vector is →u=^i20.

For the vector →v

of magnitude 40 and direction 60∘ to the horizontal axis, the vector is →v=^i40cos60∘+^j40sin60∘.

The resultant vector →w is the vector sum of the vectors, i.e.

→w=→u+→v

=^i20+^i40cos60∘+^j40sin60∘

=^i(20+40cos60∘)+^j(40sin60∘)

=^i40+^j20√3

For a vector ^ix+^jy, the magnitude of the vector is √x2+y2 and the direction above the horizontal axis is θ=tan−1(yx).

Let's use the formulas:

|→w|∠θ=√(40)2+(20√3)2∠tan−1(20√340)≈52.9∠40.9∘

The magnitude of the vector is about 53 units in the direction 41-degrees above the horizontal axis.

6 0

3 years ago

How high would you have to lift a 1000kg car to give it a potential energy of:

Elza [17]

Given parameters:

Mass of the car = 1000kg

Unknown:

Height = ?

To find the heights for the different amount potential energy given, we need to understand what potential energy is.

Potential energy is the energy at rest due to the position of a body.

It is mathematically expressed as:

P.E = mgh

m is the mass

g is the acceleration due to gravity = 9.8m/s²

h is the height of the car

Now the unknown is h, height and we make it the subject of the expression to make for easy calculation.

h = $\frac{P.E }{mg}$

For 2.0 x 10³ J;

h = $\frac{2000}{1000 x 9.8}$ = 0.204m

For 2.0 x 10⁵ J;

h = $\frac{200000}{9.8 x 1000}$ = 20.4m

For 1.0kJ = 1 x 10³J;

h = $\frac{1000}{9.8 x 1000}$ = 0.102m

5 0

3 years ago

A runner of mass 80 kg is moving at 8.0 m/s. Calculate her kinetic energy. ​

A runner of mass 80 kg is moving at 8.0 m/s. Calculate her kinetic energy.