All categories

3 years ago

What average force is necessary to bring a 50.2-kg sled from rest to a speed of 2.8 m/s in a period of 20.1 s?

1 answer:

7 0

To solve this problem we will use the concepts related to the Impulse-Momentum Theorem for which it is specified as the product between force and change in time

$\Delta p = F\Delta t$

And

\Delta p = m\Delta v

Where,

$F = Force$

$\Delta t = \text{Change in Time}$

$\Delta v = \text{Change in velocity}$

$m = mass$

Rearranging to find the Force we have that

$F = \frac{\Delta p}{\Delta t}$

Using the expression between mass and velocity

$F = \frac{m(v_f-v_i)}{\Delta t}$

Our values are given as,

$m = 50.2kg\\v_i = 0m/s \\v_f = 2.8m/s \\\Delta t = 20.1s$

Then replacing we have that

$F = 6.99N$

Therefore the average force is 6.99N

You might be interested in

A 0.0663 kg ingot of metal is heated to 241◦C

Westkost [7]

Answer:280.216j/kg°C

Explanation:

Mass of metal=0.0663kg

mass of water=0.395kg

Final temperature=27.4°C

Temperature of metal=241°C

Temperature of water=25°C

specific heat capacity of water=4186j/kg°C

0.0663xax(241-27.4)=0.395x4186x(27.4-25)

0.0663xax213.6=0.395x4186x2.4

14.16168a=3968.328

a=3968.328 ➗ 14.16168

a=280.216j/kg°C

4 0

2 years ago

Why are we not able to see immediate after we enter a dark hall from a lighter place.

Kipish [7]

Technically this is a Biology question;

The 'amount' we can see depends on how much light can get through our pupil to hit our retina.
When there is a lot of light the pupil is small; it doesn't need to be big to let a lot of light in.
When we move to a dark space there is much less light, so the pupil 'dilates' to let enough light so we can see properly.
The period in which one cant see is simply when the pupil hasn't had time to change shape yet so doesn't let in enough light.<span />

3 0

3 years ago

How much heat Q H QH does a heat pump with a coefficient of performance of 2.10 2.10 deliver when supplied with 1.82 kJ 1.82 kJ

valina [46]

The operating coefficient or performance coefficient of a heat pump is the ratio between the heating or cooling provided and the electricity consumed. The higher coefficients are equivalent to lower operating costs. The coefficient can be greater than 1, because it is a percentage of the output: losses, other than the thermal efficiency ratio: input energy. Mathematically can be written as,

$\text{Coefficient of performance} = \frac{\text{Heat extracted}}{\text{Electrical energy supplied}}$

$COP = \frac{Q}{E}\rightarrow Q =COP\times E$

Replacing,

$Q = 2.1\times 1.82kJ$

$Q = 3.822kJ$

Therefore the heat is 3.822kJ

4 0

2 years ago

A straight wire of length 4.5 cm moves at a constant speed of 5.2m/s perpendicular to its length and a uniform magnetic field. I

liraira [26]

Well you have to minus the 4.5 to 5.2 and the answer to that would be -11.5 and calculated that to be 4.5

3 0

3 years ago

Acid precipitation is caused by a mix of

saveliy_v [14]

C. sulfur dioxide, carbon dioxide, and nitrogen oxides

These three chemical compounds play a role in the chemistry of acid rain or acid precipitation. These compounds are then in the process as they evaporate are converted into acids, mainly, nitric acid and sulfuric acid. These toxic gases that composes acid precipitation is actually caused by industries, factories or plants that utilizes such chemicals and then uses a humongous amount which then is released in during the process of certain products or manufactured objects.

4 0

3 years ago