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Alex73 [517]
3 years ago
11

suppose a ball is thrown vertically upward. Eight seconds later it returns to its point of release. What is the initial velocity

of the ball?
Physics
1 answer:
valentinak56 [21]3 years ago
6 0
The ball took half of the total time ... 4 seconds ... to reach its highest
point, where it began to fall back down to the point of release.

At its highest point, its velocity changed from upward to downward. 
At that instant, its velocity was zero.

The acceleration of gravity is 9.8 m/s².  That means that an object that's
acted on only by gravity gains 9.8 m/s of downward speed every second. 

-- If the object is falling downward, it moves 9.8 m/s faster every second.

-- If the object is tossed upward, it moves 9.8 m/s slower every second.

The ball took 4 seconds to lose all of its upward speed.  So it must have
been thrown upward at  (4 x 9.8 m/s)  =  39.2 m/s .

(That's about  87.7 mph straight up.  Somebody had an amazing pitching arm.)
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Amit has found a rock in his backyard and would like to measure its mass, volume, and density. What tools can he use to perform
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Using balance, mass of the rock can be measured.

we can calculate the density using the following formula:

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Isaac Newton’s investigations of gravity explained which truth?
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A mass of 3.0 kg rests on a smooth surface inclined 34° above the horizontal. It is kept from sliding down the plane by a spring
azamat

Answer:

The spring stretched by x = 13.7 cm

Explanation:

Given data

Mass = 3 kg

k = 120 \frac{N}{m}

Angle \theta = 34°

From the free body diagram

Force acting on the box = mg sin\theta

⇒ F = 3 × 9.81 × \sin34

⇒ F = 16.45 N ------- (1)

Since box is attached with the spring so a spring force also acts on the box.

F_{sp} = k x

F_{sp} = 120 x -------- (2)

The net force acting on the body is given by

F_{net} = ma

Since acceleration of the box is zero so

F_{net} = 0

F - F_{sp} = 0

F = F_{sp}

Put the values from equation (1) & (2) we get

16.45 = 120x

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3 years ago
When force is applied to a breaker bar the torque can be calculated by multiplying the length of the lever by the?
Nimfa-mama [501]

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<h3>What is torque?</h3>

Torque is the <u>rotating equivalent</u> of force in physics and mechanics. Depending on the subject of study, it is also known as the moment, moment of force, rotating force, or turning effect. It illustrates how a force can cause a change in the body's rotational motion.

Torque is given by the formula :

                          α = r x F ( bold letters represent vector quantities)

The S.I. unit for torque is :  N - m ( Newton - meter)

<h3>How do we define 1 N-m of torque?</h3>

The newton-metre is a torque unit (also known as a moment) in the SI system. The torque produced by a one newton force applied <u>perpendicularly to the end of a one metre long</u> moment arm is known as a newton-metre.

To learn more about torque:

brainly.com/question/14970645

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