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3 years ago

What best describes the dropping height of a ball that bounced back up to a height of 45 centimeters?

1 answer:

6 0

Answer:C:Less than 45 centimeters, as the ball transforms some of its potential energy into thermal energy and sound energy

Less than 45 centimeters, as the ball transforms some of its potential energy into thermal energy and sound energy.

Although the initial energy (potential energy is preserved), the energy of deformation as the ball strikes a surface creates energy dissipation in the form of frictional heat and audible sound energy.

Every time the ball bounces, its height will be less than its previous height.

Explanation:

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Immediately after being struck by a hammer, the nail (mass of 50 g) has a velocity of 50 m/s. The total frictional force is 62.5

Marina86 [1]

Answer:

nail will stop after traveling 1000 m

Explanation:

We have given mass m = 50 gram = 0.05 kg

Frictional force which is used to stop the mass F = 62.5 kN

Initial velocity is given u = 50 m/sec

From newton's law force is equal to F = ma, here m is mass and a is acceleration

So $a=\frac{F}{m}=\frac{62.5\times 10^3}{0.05}=1.25\times 10^6m/sec^2$

As finally nail stops so final velocity v = 0 m/sec

From third equation of motion $v^2=u^2+2as$

So $0^2=50^2-2\times 1.25\times 10^6\times s$

s = 1000 m

So nail will stop after traveling 1000 m

8 0

2 years ago

A student of 4 feet tall went for swimming in a pool. He saw the depth of water in the pole less than 4 feet .Will he sink , wri

Nataly_w [17]

Answer:

he will not be drowned

Explanation:

Question says , the height of the student = 4 feet,

Depth of the pool( in feet ) be x ( say ) which is less than 4 feet,

Clearly, the depth of the pool < height of the student,

This means, if the student goes for swimming in the pool, however he does not know swimming, he will not be drowned until he is suffering from an injury or external force.

3 0

2 years ago

If a car is traveling 60 mph, its tires may have an rpm of 840. How many revolutions do the car’s tires make in one second?

Varvara68 [4.7K]

Forget about the car's speed. You don't need it.

The tires spin 840 rpm. That's 840 Revolutions per Minute .

There are 60 seconds in 1 minute. So something that happens 840 times in 1 minute happens (840 / 60) times every second.

(840 rev per minute) / (60) = 14 revs per second .

5 0

2 years ago

The famous black planet, haunch, has a radius of 106 m, a gravitational acceleration at the surface of 4 m/s2 , and the tangenti

levacccp [35]

Gravity on the surface = 4 m/s^2
Now, the acceleration due to centripetal motion, a = v^2/R

Where,
v= 10^3 m/s, R = 10^6 m
Then,
a = (10^3)^2/(10^6) = 1 m^2/s

The net gravitational acceleration = 4-1 = 3 m/s^2

The reading on the spring scale = ma = 40*3 = 120 N

6 0

3 years ago

If the total dissipated power is to be reduced by 10%, how much should the voltage be reduced to maintain the same leakage curre

harkovskaia [24]

Since P = V x I, a 10% reduction of power would lead to a 10% reduction in the product of voltage and current. What is left is 90% of the original power: .9P = .9(V x I). If we assume that current must be the same, then we can regroup the terms on the right-hand side as follows: .9P = (.9V) x I In this case, voltage is also reduced by 10% (100% - 90% = 10%).

6 0

3 years ago