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2 years ago

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Hunk travelled 540 km at an average speed of 90 km/h. If Tim completed the same amount of distance with 1 hour and 30 min less t

han Hunk, what was Tim's average speed for the whole journey? km/h

1 answer:

lina2011 [118]2 years ago

8 0

Answer:120

Explanation:it just is trust me

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2.A chef leaves a copper spoon, a wooden spoon, and a steel spoon in a pot of boiling soup for several minutes. Which spoon shou

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Answer:

Option B

Explanation:

The correct answer is Option B

After leaving the spoon of copper , steel and wooden in the soup for several minute chef can grab Wooden spoon with bare hand.

Wooden material are insulator of heat means heat does not transfer through the wooden material.

where as heat transfer take place in steel as well as copper and chef will not be able to lift the spoon bare hand.

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The findings of Henri Becquerel and the Curies helped to discredit what notion held for a very long time? That matter can never

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That matter s indivisible and indestructible. This is because they discovered that certain elements, thought to be indivisible, can breakdown by radioactive decay and emit smaller, high energy particles and/or photons.

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Which of the following is an example of velocity?

pav-90 [236]

C :) cause a direction has nothing do do with velocity !

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What are the types of pulleys

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I found this on google
<span>There are three main types of pulleys: fixed, movable, and compound. A fixed pulley's wheel and axle stay in one place. A good example of a fixed pulley is a flag pole: When you pull down on the rope, the direction of force is redirected by the pulley, and you raise the flag.</span>

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A projectile (mass = 0.15 kg) is fired at and embeds itself in a stationary target (mass = 2.44 kg). With what percentage of the

Bess [88]

Answer:

38.6 %

Explanation:

First of all, we have to calculate the final velocity of the block-bullet system. We can apply the law of conservation of momentum:

$m u + M U = (m+M)v$

where

m = 0.15 kg is the mass of the bullet

u is the initial velocity of the bullet

M = 2.44 kg is the mass of the block

U = 0 is the initial velocity of the block (it is at rest)

v is the final velocity of the bullet+block

Solving for v,

$v=\frac{mu}{m+M}$

The total initial kinetic energy of the system is just the kinetic energy of the bullet:

$K = \frac{1}{2}mu^2$

While the final kinetic energy of the block+bullet is:

$K' = \frac{1}{2}(m+M) v^2 = \frac{1}{2}(m+M) \frac{(mu)^2}{(m+M)^2}=\frac{1}{2} \frac{m}{m+M}u^2$

So the fraction of kinetic energy lost is

$\frac{K-K'}{K}=\frac{\frac{1}{2}mu^2 - \frac{1}{2}\frac{m}{m+M}u^2}{\frac{1}{2}mu^2}=\frac{m-\frac{m}{m+M}}{m}=\frac{0.15-\frac{0.15}{0.15+2.44}}{0.15}=0.614$

And so, the fraction of kinetic energy left in the projectile after he flies off the block is

1 - 0.614 = 0.386 = 38.6 %

4 0

2 years ago