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3 years ago

What do you mean by negative acceleration? can an accelerating automobile starting from rest have a negative acceleration

Physics

1 answer:

Irina-Kira [14]3 years ago

4 0

Explanation:

The acceleration tells us how the speed changes per unit of time. If we say a body has a negative acceleration we are saying that its speed decreases over time.

If a body has a positive initial velocity and a negative acceleration: the velocity decreases. On the contrary, if the automobile has a negative initial velocity (in the opposite direction) and a negative acceleration: the velocity is increasing. Thus, an accelerating automobile starting from rest can have a negative acceleration.

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A 3.47-m rope is pulled tight with a tension of 106 N. A wave crest generated at one end of the rope takes 0.472 s to propagate

konstantin123 [22]

Answer:

The mass of the rope is 1.7 kg.

Explanation:

Given;

length of the rope, L = 3.47 m

tension on the rope, T = 106 N

period of the wave, t = 0.472 s

frequency of the is calculated as;

$f = \frac{1}{t} \\\\f = \frac{1}{0.472} \\\\f = 2.1186 \ Hz$

the speed of the wave is calculated as;

$v = \sqrt{\frac{T}{\mu} }$

where;

v is speed of the wave = fλ

λ is the wavelength

μ is mass per unit length

$f\lambda = \sqrt{\frac{T}{\mu} } \\\\f(2l) = \sqrt{\frac{T}{\mu} } \\\\2fl = \sqrt{\frac{T}{\mu} } \\\\(2fl)^2 = \frac{T}{\mu}\\\\4f^2l^2 =\frac{T}{\mu}\\\\\mu = \frac{T}{4f^2l^2}\\\\\frac{m}{l} = \frac{T}{4f^2l^2}\\\\m = \frac{T}{4f^2l}\\\\m = \frac{106}{4(2.1186)^2(3.47)}\\\\m = 1.7 \ kg$

Therefore, the mass of the rope is 1.7 kg.

6 0

3 years ago

Erica throws a tennis ball against a wall, and it bounces back. Which force is responsible for sending the ball back to Erica?

Anna71 [15]

OPTIONS :

A.) the force that the ball exerts on the wall

B.) the frictional force between the wall and the ball

C.) the acceleration of the ball as it approaches the wall

D.) the normal force that the wall exerts on the ball

Answer: D.) the normal force that the wall exerts on the ball

Explanation: The normal force acting on an object can be explained as a force experienced by an object when it comes in contact with a flat surface. The normal force acts perpendicular to the surface of contact.

In the scenario described above, Erica's tennis ball experiences an opposite reaction after hitting the wall.This is in relation to Newton's 3rd law of motion, which states that, For every action, there is an equal and opposite reaction.

The reaction force in this case is the normal force exerted on the ball by the wall perpendicular to the surface of contact.

8 0

3 years ago

HELPPPPPPPPP Which option is a series of movement exercises for physical and mental health and is based on Hindu philosophy? O p

nika2105 [10]

Answer:

The correct answer is option ( D ) Yoga

Explanation:

hope it helps you dear :)

have a nice day

7 0

3 years ago