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dangina [55]
3 years ago
10

A 2kg watermelon is dropped from a 4m tall roof a) use the appropriate kinematic equations to determine the instantaneous veloci

ty of the watermelon as its strikes the ground below?
Physics
1 answer:
Ivenika [448]3 years ago
6 0

Answer:

8.85m/s

Explanation:

The potential energy the watermelon held before dropping is Ep=mgh=2*9.8*4=78.4J.

When it strikes the ground, all of its Ep will transfer into Ek, so 1/2*m*v^2=78.4.

We already knew that m=2, so insert that in, we will get the V^2=78.4 m/s, V=8.85 m/s

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A force of 100. newtons is used to move an object a distance of 15 meters with a power of 25 watts. Find the time it takes to do
Flauer [41]
<h3>It takes 60 seconds to do the work</h3>

<em><u>Solution:</u></em>

Given that,

Force = 100 newtons

Distance = 15 meters

Power = 25 watts

To find: time it takes to do the work

<em><u>Find the work done:</u></em>

work = force \times displacement\\\\work = 100\ newtons \times 15\ meters\\\\work = 1500\ joule

<em><u>Find the time taken</u></em>

power = \frac{work}{time}\\\\25\ watts = \frac{1500\ joule}{time}\\\\time = \frac{1500\ joule}{25\ watt}\\\\time = 60\ second

Thus it takes 60 seconds to do the work

3 0
3 years ago
A chunk of ice with a mass of 1.2 kg melts and absorbs 3.33 x 10³J of energy. Which best describes what has happened in this sys
Maurinko [17]

Answer:

- Its entropy increases.

Explanation:

Entropy is defined as a 'measure of the amount of energy in a physical system that cannot be used to do work.' It is also employed to denote randomness, disorder, or uncertainty of the arrangement/system. In the given system, the melting of ice denotes the 'increase in entropy' as the amount of energy unavailable to do work increases('absorbs 3.33 x 10³J of energy'). Thus, <u>this signifies that the entropy increases with a rise in temperature as it allows the substance to have greater kinetic energy</u>.

3 0
3 years ago
Ntally Check for Understanding
Wewaii [24]

Answer: 34

Explanation:

34

3 0
3 years ago
for any object suspended by any number of ropes, wires, or chains, how is the total amount of tension (tension in each rope adde
Sveta_85 [38]

Answer:

To calculate the tension on a rope holding 1 object, multiply the mass and gravitational acceleration of the object. If the object is experiencing any other acceleration, multiply that acceleration by the mass and add it to your first total.

Explanation:

The tension in a given strand of string or rope is a result of the forces pulling on the rope from either end. As a reminder, force = mass × acceleration. Assuming the rope is stretched tightly, any change in acceleration or mass in objects the rope is supporting will cause a change in tension in the rope. Don't forget the constant acceleration due to gravity - even if a system is at rest, its components are subject to this force. We can think of a tension in a given rope as T = (m × g) + (m × a), where "g" is the acceleration due to gravity of any objects the rope is supporting and "a" is any other acceleration on any objects the rope is supporting.[2]

For the purposes of most physics problems, we assume ideal strings - in other words, that our rope, cable, etc. is thin, massless, and can't be stretched or broken.

As an example, let's consider a system where a weight hangs from a wooden beam via a single rope (see picture). Neither the weight nor the rope are moving - the entire system is at rest. Because of this, we know that, for the weight to be held in equilibrium, the tension force must equal the force of gravity on the weight. In other words, Tension (Ft) = Force of gravity (Fg) = m × g.

Assuming a 10 kg weight, then, the tension force is 10 kg × 9.8 m/s2 = 98 Newtons.

7 0
3 years ago
Where is heat transferred by conduction in a lava lamp?
Semmy [17]
It is transferred by direct contact, say you touched it, you would feel the heat
8 0
3 years ago
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