All categories

3 years ago

25 points!

Physics

1 answer:

Veronika [31]3 years ago

8 0

Refer to the diagram shown below.

At A, the boy begins walking up the stairs.

At B, the boy is at the top of the slide. He has acquired PE (potential energy).
The value of the PE is
(50 kg)*(9.8 m/s²)*(11.5 m) = 5635 J

At C, the boy has KE (kinetic energy).
The value of the KE is
(1/2)*(50 kg)*(12 m/s)² = 3600 J

Energy is lost between B and C due to friction.
The lost energy is
5635 - 3600 = 2035 J

The distance traveled along the slide is 108 m.
If F = the average frictional force, then
(F N)*(108 m) = 2035 J
F = 18.84 N

Answers:
(a) The mechanical energy lost by sliding is 2035 J.
(b) The average frictional force is 18.84 N

You might be interested in

1. If you walk 10 blocks North, then turn around and walk 4 Blocks to the South before stopping to answer your phone, then turn

icang [17]

Answer: 13 blocks

Explanation:10-4+7=13

4 0

3 years ago

A 1.1-kg uniform bar of metal is 0.40 m long and has a diameter of 2.0 cm. When someone bangs one end of this bar, a 1.5 MHz sho

lyudmila [28]

Answer:

$\lambda = 2.22\times 10^{-3}\ m$

Explanation:

Given,

mass of the bar = 1.1 Kg

length of rod, l = 0.40 m

diameter of the rod, d = 2 cm

frequency, f = 1.5 MHz

time, t = 0.12 ms

wavelength of the shock wave = ?

Speed of the wave = $\dfrac{L}{t}=\dfrac{0.40}{0.12\times 10^{-3}}$

v = 3333.33 m/s

wavelength of the wave

$\lambda = \dfrac{v}{f}= \dfrac{3333.33}{1.5\times 10^6}$

$\lambda = 2.22\times 10^{-3}\ m$

6 0

3 years ago

A straight wire 0.10 m long carrying a current of 2.0 A is at right angles to a magnetic field. The force on the wire is 0.04 N.

Vladimir79 [104]

Answer:

The strength of magnetic field is 0.2 Tesla.

Explanation:

Data from the question is

Length (L) of wire ; L=0.10 m

Current in wire ; I= 2.0 A

Force on wire ; F = 0.04 N

Angle = Right angle So, $\theta$ $\thita = 90^{o}$

Now ,

We have to find the magnetic Field strength (B)

For this formula for Force on wire in magnetic field is

$F = I \times B \times L \times sin(\theta)$

Further modified as

$B = \frac{F}{I \times L \times sin(\theta)}$

Now insert values in the formula

$B = \frac{0.04N}{2.0A \times 0.10 m \times sin(90^{0})}$

$B = 0.2 T$

So, the strength of magnetic field is 0.2 Tesla.

8 0

4 years ago

Physics!!! Please help!!!!!!!

Marianna [84]

Answer:

it is a very good morning amor de g the first paragraph of the first paragraph of the first paragraph of the first paragraph of the first paragraph of the first paragraph of 88th paragraph of the first paragraph

8 0

3 years ago

Consider the following objects and their locations. Object a 2-kg object 5 cm above the floor Object b 2-kg object 120 cm above

Nataly [62]

Answer:

The gravitational acceleration is same for all objects.

a = b = c = d

Explanation:

Acceleration due to gravity or gravitational acceleration is the force exerted by Earth on unit mass of an object.

Acceleration due to gravity doesn't depend on the height of the object when the height is object is near to the surface of the Earth. Only when the height is comparable to the radius of the Earth, the value of gravitational acceleration changes.

But for the objects here, the gravitational acceleration is independent of the mass or height of the objects and has a constant value of 9.8 m/s².

Therefore, the gravitational acceleration of all the objects is same.

If 'a', 'b', 'c', and 'd' represent gravitational accelerations of objects 'a', 'b', 'c', and 'd' respectively, then a = b = c = d.

5 0

3 years ago