1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Y_Kistochka [10]
3 years ago
13

How much work (in j) must be done to lift a stack of bricks, which has a mass of 400 kg, from the ground to a height of 3 m? (g

= 10 m/s2)?
Physics
1 answer:
svetoff [14.1K]3 years ago
6 0
Given: Mass m = 400 Kg;   Height h = 3 m;     g = 10 m/s²

Required:  Work = ?

Formula: Work = Force x distance  F = ma    a = g    F = mg

W = fd

W = mgh

W = (400 Kg)(10 m/s²)( 3 m)

W = 12,000 Kg.m²/s²

W = 12,000 J

You might be interested in
A cylindrical can 150 mm in diameter is filled to a depth of 100 mm with a fuel oil. The oil has a mass of 1.56 kg. Calculate it
Kazeer [188]

Answer:

Density (φ) = 0,8827 Kg/L

Specific weight (Ws) = 8,65 N/L

Specific gravity (Gs) = 0,8827 (without unit)

Explanation:

The density formula: φ = \frac{m}{V}

I know the mass "m", I need to find out the volume of the cylinder (V)

V = π* r²*h

The radius "r" is equal to half the diameter (150mm) = 75mm

Now I can find out the density (φ)

φ = \frac{1,56Kg}{1,767145L} = 0,8827 Kg/L

The specific weight (Ws) is the relationship between the weight of substance (oil) and its volume. We apply the following formula:

Ws = φ*g

(g = gravity = 9,8 m/s²)

Finally, specific gravity (Gs) is the ratio between the density of a substance (oil) "φ(o)" and the density of water "φ(w)" :

Gs = φ(o) /  φ(w)

(φ(w) = 1 Kg/L

Hope this can help you !!

3 0
3 years ago
An AM radio station broadcasts isotropically (equally in all directions) with an average power of 3.80 kW. A receiving antenna 7
Alecsey [184]

Answer:0.1759 v

Explanation:

Intensity of wave at receiver end is

I=\frac{P_{avg}}{A}

I=\frac{3.80\times 10^3}{4\times \pi \times \left ( 4\times 1609.34\right )^2}

I=7.296\times 10^{-6} W/m^2

Amplitude of electric field at receiver end

E_{max}=\sqrt{2I\mu _0c}

Amplitude of induced emf

=E_{max}d

=\sqrt{2\times 7.29\times 10-6\times 4\pi \times 3\times 10^8}\times 0.75

=17.591\times 10^{-2}=0.1759 v

7 0
3 years ago
A 70.0 kg ice hockey goalie, originally at rest, has a 0.110 kg hockey puck slapped at him at a velocity of 31.5 m/s. Suppose th
NISA [10]

Answer

given,

mass of the goalie(m₁) = 70 kg

mass of the puck (m₂)= 0.11 kg

velocity of the puck = 31.5 m/s

elastic collision

v_1=\dfrac{m_2-m_1}{m_1+m_2}v_1+\dfrac{2m_2}{m_1+m_2}v_2

v_{pf}=\dfrac{0.11-70}{0.11+70}31.5+\dfrac{2m_2}{m_1+m_2}\times (0)

v_{pf}=-31.4\ m/s

v'_2 = \dfrac{2m_1v_1}{m_1+m_2}-\dfrac{(m_2-m_1)v_2}{m_2+m_1}

v_{gf} = \dfrac{2\times 0.11\times 31.5}{0.11+70}-\dfrac{(0.11-70)\times 0}{m_1+m_2}

v_{gf} = \dfrac{2\times 0.11\times 31.5}{0.11+70}

v_{gf} = 0.0988\ m/s

4 0
3 years ago
A 1200 kg car reaches the top of a 100 m high hill at A with a speed vA. What is the value of vA that will allow the car to coas
Pavel [41]

Complete question is:

A 1200 kg car reaches the top of a 100 m high hill at A with a speed vA. What is the value of vA that will allow the car to coast in neutral so as to just reach the top of the 150 m high hill at B with vB = 0 m/s. Neglect friction.

Answer:

(V_A) = 31.32 m/s

Explanation:

We are given;

car's mass, m = 1200 kg

h_A = 100 m

h_B = 150 m

v_B = 0 m/s

From law of conservation of energy,

the distance from point A to B is;

h = 150m - 100 m = 50 m

From Newton's equations of motion;

v² = u² + 2gh

Thus;

(V_B)² = (V_A)² + (-2gh)

(negative next to g because it's going against gravity)

Thus;

(V_B)² = (V_A)² - (2gh)

Plugging in the relevant values;

0² = (V_A)² - 2(9.81 × 50)

(V_A) = √981

(V_A) = 31.32 m/s

3 0
3 years ago
A force of 450 N moves a body through 300 cm in the direction of force. Calculate the work
OlgaM077 [116]

Answer:

150J

Explanation:

Formula : <u>Work</u><u> </u><u>done</u>

Force x distance

work done = force x distance

Distance should be measured in meters

300÷100=3m

work done = 450 x 3

=150J

3 0
2 years ago
Other questions:
  • A person steps off the end of a 3.45 � high diving board and drops to the water below. (a) How long does it take for the person
    8·1 answer
  • A positron undergoes a displacement ∆r= 2i -3j+6k, ending with the position vector r= 3j-4k, in meters. what was the positron's
    12·1 answer
  • Which food provides the body with energy in the form of carbohydrates
    7·2 answers
  • The temperature of a gas is increased from 125 celsius inside a rigid container. The original pressure of a gas was 1.22atm, wha
    14·1 answer
  • The section of the small intestine between the duodenum and ilium?
    10·2 answers
  • Plz help me on science about cells
    7·1 answer
  • What are the largest and smallest resistances you can obtain by connecting a 36.0-Ω , a 50.0-Ω , and a 700-Ω resistor together?
    6·1 answer
  • Calculate the electric current that flows through a electric heater of power 1000watt when collected with 220 volt ac supply
    11·1 answer
  • Will give correct answer brainliest
    13·2 answers
  • You are walking back toward the back of a bus that is moving forward with a constant velocity. Describe your motion relative to
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!