Please help I'm stuck on these 2 problems would help so much!! 10 POINTS Thanks!

A body of mass 100g moving with a velocity of 10.0m/s collides with a wall .if after the collision it moves with a velocity of 2

ch4aika [34]

Answer:

-1.2 kg - m/s

Explanation:

$\pink{\frak{Given}}\begin{cases}\textsf{ A body of mass 100g moving with a velocity of 10.0m/s collides with a wall .}\\\textsf{ After the collision it moves with a velocity of 2.0m/s in the opposite direction.}\end{cases}$

And we need to find out the change in momentum of the body . Here ,

velocity before collision (u) = 10m/s
velocity after collision (v) = 2m/s .

We know that momentum is defined as amount of motion contained in a body . Mathematically ,

$\sf\longrightarrow momentum (p)= mass(m) * velocity(v)$

Therefore change in momentum will be,

$\sf\longrightarrow \triangle p = mv - mu$

Since the direction of velocity changes after the collision , the velocity will be -2m/s .

$\sf\longrightarrow \Delta p = 100g( -2m/s -10m/s) \\$

$\sf\longrightarrow \Delta p =\dfrac{100}{1000}kg ( -12m/s) \\$

$\sf\longrightarrow \Delta p = 0.1 kg * -12m/s \\$

$\sf\longrightarrow \boxed{\bf \Delta p = -1.2 \ kg-m/s} \\$

7 0

2 years ago

A truck is travelling at 30km/hr with engine delivering a driving force of 800n to the road

Pavel [41]

Power = (force) x (distance / time) = force x speed .

We know the force = 800N.
We have a speed = 30km/hr, but in order to use it in the power formula,
it has to be in meters/second, so we have some work to do first.

(30 km/hr) x (1,000 m/km) x (1 hr / 3,600 sec) = 300 / 36 m/sec .

Power = (force) x (speed) = (800 N) x (300/36 m/s) = 6-2/3 kilowatts 

Work = (power) x (time) = (6,666-2/3 joule/sec) x (25sec) = 166,666-2/3 joules.

The figure for power is slightly weird ... 746 watts = 1 horsepower,
so the truck's engine is only delivering about 8.9 horsepower.
Very fuel-efficient, but I don't think they drive trucks that way.

4 0

2 years ago

How do you best describe hypothesis? A. a carefully researched answer

Kamila [148]

A hypothesis is a possible theory to how something might work. The answer is D.

3 0

3 years ago

What is the gravitational force of attraction between a planet and a 17-kilogram mass that is falling freely toward the surface

PolarNik [594]

Answer:

a. 150 N

Explanation:

Gravitational Force: This is the force that act on a body under gravity.

The gravitational force always attract every object on or near the earth's surface. The earth therefore, exerts an attractive force on every object on or near it.

The S.I unit of gravitational force is Newton(N).

Mathematically, gravitational force of attraction is expressed as

(i) F = GmM/r² ........................ Equation 1 ( when it involves two object of different masses on the earth)

(ii) F = mg ............................... Equation 2 ( when it involves one mass and the gravitational field).

Given: m = 17 kg, g = 8.8 m/s²

Substituting into equation 2,

F = 17(8.8)

F = 149.6 N

F ≈ 150 N.

Thus the gravitational force = 150 N

The correct option is a. 150 N

5 0

2 years ago

An artificial satellite is in a circular orbit around a planet of radius r = 5.25 Ã 10^3 km at a distance d = 450.0 km from the

kirill [66]

Answer:

3020.68 kg/m^3

Explanation:

r = 5.25 x 10^3 km = 5.25 x 10^6 m, d = 450 km = 450 x 10^3 m

T = 2.15 hours = 2.15 x 3600 second = 7740 second

Let the density of the planet is ρ and M be the mass of planet.

The formula for the orbital velocity is

$v = \sqrt{\frac{GM}{r+d}}$

Time period is given by

$T = {\frac{2\pi (r+d)}{v}}$

$T = \frac{2\pi (r +d)^{1.5}}{\sqrt{GM}}$

$7740= \frac{2\pi (5700\times 1000)^{1.5}}{\sqrt{6.67\times 10^{-11}M}}$

M = 1.83 x 10^24 kg

Density = mass / Volume

ρ = 1.83 x 10^24 / (4/3 x 3.14 x (5.25 x 10^6)^3)

ρ = 3020.68 kg/m^3

6 0

2 years ago