A tennis ball is dropped from a height of 1.21m above the ground. Calculate its velocity when it is 0.27m from the ground.

How much work can be done by a 50w motor in 5 sec?

Vaselesa [24]

A 50w motor can do 500w in 5 seconds

4 0

3 years ago

During a braking test, a car is brought to rest beginning from an initial speed of 60 mi/hr in a distance of 120 ft. With the sa

maw [93]

Answer:

Explanation:

Given

Initial speed $u=60\ mi/hr\approx 88\ ft/s$

distance traveled before coming to rest $d_1=120\ ft$

using equation of motion

$v^2-u^2=2as$

where v=final velocity

u=initial velocity

a=acceleration

s=displacement

$0-(88)^2=2\times a\times 120---1$

for $u_2=80\ mi/hr\approx 117.33\ ft/s$

using same relation we get

$0-(117.33)^2=2\times a\times (d_2)----2$

divide 1 and 2 we get

$(\frac{88}{117.33})^2=\frac{120}{d_2}$

$d_2=213.32\ ft$

So a distance if 213.32 ft is required to stop the vehicle with 80 mph speed

8 0

3 years ago

A man whose mass is 90 kg is 6.38x106m away from the center of the earth. If the Earth’s mass is6x1024kgand the constant Gis 6.6

inysia [295]

Answer: force of gravity is 885N

Explanation:

8 0

3 years ago

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What kind of stars make up the galactic nucleus?

Hatshy [7]

I think the correct answer would be old and metal poor stars are found in the galactic nucleus. This nucleus us a region in the center of a galaxy which contains a higher luminosity than other parts. It produces very high amounts of energy. Hope this helps.

4 0

3 years ago

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The current theory of the structure of the

IRISSAK [1]

1) The mass of the continent is $3.3\cdot 10^{21} kg$