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2 years ago

4. An object is moving with an initial velocity of 9 m/s. It accelerates at a rate of 1.5

Physics

1 answer:

Mazyrski [523]2 years ago

7 0

Answer:

11.87 ms⁻¹

Explanation:

You can use the kinematic equation

v² = u² + 2as

Where v = final velocity

u = initial velocity

a = acceleration

s = displacement

v² = 9² + 2×1.5×20

So you get v = 11.87 ms⁻¹

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The current theory of the structure of the Earth, called plate tectonics, tells us that the continents are in constant motion.

lesya [120]

Answer:

(a) m = 1.6 x 10²¹ kg

(b) K.E = 2.536 x 10¹¹ J

Explanation:

(a)

First we find the volume of the continent:

V = L*W*H

where,

V = Volume of Slab = ?

L = Length of Slab = 4450 km = 4.45 x 10⁶ m

W = Width of Slab = 4450 km = 4.45 x 10⁶ m

H = Height of Slab = 31 km = 3.1 x 10⁴ m

Therefore,

V = (4.45 x 10⁶ m)(4.45 x 10⁶ m)(3.1 x 10⁴ m)

V = 6.138 x 10¹⁷ m³

Now, we find the mass:

m = density*V

m = (2620 kg/m³)(6.138 x 10¹⁷ m³)

m = 1.6 x 10²¹ kg

(b)

The kinetic energy will be:

K.E = (1/2)mv²

where,

v = speed = (1 cm/year)(0.01 m/1 cm)(1 year/365 days)(1 day/24 h)(1 h/3600 s)

v = 3.17 x 10⁻¹⁰ m/s

Therefore,

K.E = (1/2)(1.6 x 10²¹ kg)(3.17 x 10⁻¹⁰ m/s)²

K.E = 2.536 x 10¹¹ J

(c)

For the same kinetic energy but mass = 77 kg:

K.E = (1/2)mv²

2.536 x 10¹¹ J = (1/2)(77 kg)v²

v = √(2)(2.536 x 10¹¹ J)

v = 7.12 x 10⁵ m/s

7 0

2 years ago

Which subatomic particle has the least mass?

goblinko [34]

Answer:

electron

Explanation:

6 0

3 years ago

Part of one row of the periodic table is shown. 4 blue boxes in a row. The first has S n at the center and 50 above with tin and

nydimaria [60]

Answer:

Atoms of tellurium (Te) have the greatest average number of neutrons equal to 76.

Explanation:

In the periodic table, Elements are represented with their respected symbols. Above the symbol is the elements atomic number which is equal to the number of protons in each atom. Below the symbol is the mass number of that element which is roughly equal to the sum of neutrons and protons of that atom.

To calculate the number of neutrons we can take the difference of Atomic number and mass number:

Number of neutrons = mass number - atomic number

- Tin:

Atomic number = 50

Mass number = 119

Number of neutrons = mass number - atomic number = 119 - 50

Number of neutrons = 69

- Antimony(Sb):

Atomic number = 51

Mass number = 122

Number of neutrons = mass number - atomic number = 122 - 51

Number of neutrons = 71

- Tellurium(Te):

Atomic number = 52

Mass number = 128

Number of neutrons = mass number - atomic number = 128 - 52

Number of neutrons = 76

- Iodine(I):

Atomic number = 53

Mass number = 127

Number of neutrons = mass number - atomic number = 127 - 53

Number of neutrons = 74

Here, the greatest number of neutrons is for the atoms of Tellurium(Te).

7 0

3 years ago

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andriy [413]

Answer:

Explanation:

3 0

2 years ago

Read 2 more answers

A baseball pitcher throws a ball at 40 ms^-1. if the acceleration is approximately constant over a distance of 2 m, how large is

Reil [10]

We have the equation of motion $v^2=u^2+2as$ , where v i the final velocity, u is the initial velocity, a is the acceleration and s is the displacement

Here final velocity, v = 40m/s

Initial velocity, u = 0 m/s

Displacement s = 2 m

Substituting $40^2=0^2+2*a*2\\ \\ a=400m/s^2$

So the baseball pitcher accelerates at 400m/ $s^2$ to release a ball at 40 m/s.

4 0

3 years ago