All categories

3 years ago

The power rating of an electric lawn mower is 2000 watts if lawnmower is used for 120 seconds how many joules of work van it do

1 answer:

4 0

1 watt = 1 joule/sec

2,000 watts = 2,000 joules/sec

   (2,000 joule/sec) x (120 sec)

      = (2,000 x 120) (joule-sec/sec)

      = 240,000 joules .

You might be interested in

A constant force pushes a 5 kg brick at 10 N. If the mass was tripled, what would happen to the acceleration if the same force i

hjlf

Explanation:

The original acceleration is:

∑F = ma

10 N = (5 kg) a

a = 2 m/s²

If the mass is tripled, the new acceleration is:

∑F = ma

10 N = (15 kg) a

a = 0.67 m/s²

The acceleration is reduced by a factor of 3.

5 0

3 years ago

Read 2 more answers

cupoosta [38]

Answer:

<h3>The answer is 1.92 g/cm³</h3>

Explanation:

The density of a substance can be found by using the formula

$density = \frac{mass}{volume} \\$

From the question

mass = 2.5 g

Volume = 1.3 cm³

We have

$density = \frac{2.5}{1.3} \\ = 1.923076...$

We have the final answer as

Hope this helps you

5 0

3 years ago

Why Are Atoms Neutral?

Pachacha [2.7K]

Answer is C. when protons are equal to electrons their charges cancel out making it neutral because electrons have a charge of negative one and when you combine them positive 1 and negative 1 is 0.

5 0

3 years ago

A comet is in an elliptical orbit around the Sun. Its closest approach to the Sun is a distance of 4.7 1010 m (inside the orbit

Lubov Fominskaja [6]

Answer:

58515.9 m/s

Explanation:

We are given that

$d_1=4.7\times 10^{10} m$

$v_i=9.5\times 10^4 m/s$

$d_2=6\times 10^{12} m$

We have to find the speed (vf).

Work done by surrounding particles=W=0 Therefore, initial energy is equal to final energy.

$K_i+U_i=K_f+U_f$

$\frac{1}{2}mv^2_i-\frac{GmM}{d_1}=\frac{1}{2}mv^2_f-\frac{GmM}{d_2}$

$\frac{1}{2}v^2_i-\frac{GM}{d_1}+\frac{GM}{d_2}=\frac{1}{2}v^2_f$

$v^2_f=2(\frac{1}{2}v^2_i-\frac{GM}{d_1}+\frac{GM}{d_2})$

$v_f=\sqrt{2(\frac{1}{2}v^2_i-\frac{GM}{d_1}+\frac{GM}{d_2})}$

Using the formula

$v_f=\sqrt{v^2_i+2GM(\frac{1}{d_2}-\frac{1}{d_1})}$

$v_f=\sqrt{(9.5\times 10^4)^2+2\times 6.7\times 10^{-11}\times 1.98\times 10^{30}(\frac{1}{6\times 10^{12}}-\frac{1}{4.7\times 10^{10})}$

Where mass of sun= $M=1.98\times 10^{30} kg$

$G=6.7\times 10^{-11}$

$v_f=58515.9 m/s$

4 0

3 years ago

The damage caused by electric shock depends on the current flowing through the body; 1 ma can be felt and 5 ma is painful. above

WARRIOR [948]

We can solve the problem by using Ohm's law.

The resistance of the person, with dry skin, is $R=60000 \Omega$ . In order to be felt, the current must be at least
$I=1 mA=0.001 A$

Ohm's law gives us the relationship between current and voltage:
$V=IR$
where
I is the current
R the resistance
V the voltage

Using the data of the problem, we find that the minimum voltage needed is
$V=IR=(0.001 A)(60000 \Omega)=60 V$

3 0

3 years ago