Item 2

Determine whether the following statements are true or false and give an explanation or counter example. a. If the acceleration

tester [92]

Answer:

If the acceleration of an object remains constant, then its velocity is constant. False

If the acceleration of an object moving along a line is always 0, then its velocity is constant. True

It is impossible for the instantaneous velocity at all times aless than or equalstless than or equalsb to equal the average velocity over the interval aless than or equalstless than or equalsb. True

A moving object can have negative acceleration and increasing speed. False

Explanation:

First of all, before we can talk of acceleration, then there must be a change in velocity. If the velocity of a body is constant, then there will not be any acceleration at all.

If the acceleration is zero, then there is no change in velocity, the velocity is constant.

The instantaneous velocity is always changing all through the motion hence it cannot be determined at all times to equal the average velocity.

If the acceleration is negative, it simply means that the velocity is decreasing with time. Hence there can't be a negative acceleration and increasing velocity.

5 0

3 years ago

A dragster completed a 402.3-(0.2500-mi) run in 5.023s. If the car had a constant acceleration, what was its acceleration and fi

Ray Of Light [21]

Answer:

v = 80.092 m/s

a = 15.945 m/s²

Explanation:

Given,

The distance completed by the dragster, d = 402.3 m

The time taken by the dragster to complete that distance is, t = 5.023 s

The initial velocity of the dragster, u = 0

The final velocity of the dragster, v = ?

The acceleration of the dragster, a = ?

The velocity of the body is given by the formula

v = d/t m/s

Substituting the above values inn the equation

v = 402.3 m / 5.023 s

= 80.092 m/s

So, the velocity of the dragster is, v = 80.092 m/s

The acceleration of the body is given by the formula

a = (v - u)/t m/s²

Substituting the above values in the equation

= (80.092 - 0) / 5.023

= 15.945 m/s²

Hence, the acceleration of the dragster is, a = 15.945 m/s²

6 0

3 years ago

A 56-kg skater initially at rest throws a 5.0-kg medicine ball horizontally to the left. Suppose the ball is accelerated through

aniked [119]

Answer:

$a_2=24.5\ \text{m/s}^2$ towards right

$a_1=2.1875\ \text{m/s}^2$ towards left

Explanation:

$m_1$ = Mass of skater = 56 kg

$m_2$ = Mass of ball = 5 kg

v = Final velocity of ball = 7 m/s

u = Initial velocity of ball = 0

s = Distance the ball moved in the hand of the skater = 1 m

Moving left is considered and moving right is considered positive.

From kinematic equations of motion we have

$v^2-u^2=2as\\\Rightarrow a=\dfrac{v^2-u^2}{2s}\\\Rightarrow a=\dfrac{7^2-0^2}{2\times 1}\\\Rightarrow a=24.5\ \text{m/s}^2$

So, the ball will move towards right with a magnitude of acceleration $a_2=24.5\ \text{m/s}^2$ .

The force on the ball will be

$F_2=m_2a_2\\\Rightarrow F_2=5\times 24.5\\\Rightarrow F_2=122.5\ \text{N}$

The force on the ball is $122.5\ \text{N}$

The reaction force on the skater will be equal to the force on the ball but will have opposite direction.

$-F_1=F_2\\\Rightarrow -m_1a_1=F_2\\\Rightarrow a_1=-\dfrac{122.5}{56}\\\Rightarrow a_1=-2.1875\ \text{m/s}^2$

So, the skater will move towards left with a magnitude of acceleration $2.1875\ \text{m/s}^2$

4 0

3 years ago

The________ channels sound to the eardrum.

inn [45]

The external auditory meatus, or ear canal, funnels sound to the eardrum. It is part of the outer ear.

6 0

3 years ago

Is telekinesis real??? I really wanna start learning it!

Lesechka [4]

Answer:

if you only have to control your chakra and know how to get all your vibes to pass it to objects and it takes time to practice

4 0

3 years ago