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3 years ago

A net force xf acts on an object. what does this mean?

1 answer:

8 0

Answer: 6- for an object to accelerate, Newton's law #2 tells us there must be a force acting on it. F=ma the effect of a force is to accelerate the mass . It cannot be 1, because the force must be centripetal to move the object in a circle. it can't be 2 because if an object is accelerating the velocity cannot be constant as it is moving faster. It can't be 3 because a stationary object has a net force of 0. 4 has nothing to do with the question. 5- no force is needed for uniform motion. 7- that is impossible.

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Mass can be considered concentrated at the center of mass for rotational motion.Select one:TrueFalse

frez [133]

iIn this case the mass of a body cannot be considered to be concentrated at the centre of mass of the body for the purpose of computing the rotational motion

Therefore the answer is False

6 0

1 year ago

The pressure of a gas produces a net force (the sum of all the forces) at ____ angles to the wall of a container.

ivanzaharov [21]

Answer: RIGHT angles

Explanation:

7 0

3 years ago

A 35 g steel ball is held by a ceiling-mounted electromagnet 4.0 m above the floor. A compressed-air cannon sits on the floor, 4

HACTEHA [7]

Answer:

7.9 m/s

Explanation:

When both balls collide, they have spent the same time for their motions.

Motion of steel ball

This is purely under gravity. It is vertical.

Initial velocity, u = 0 m/s

Distance, s = 4.0 m - 1.2 m = 2.8 m

Acceleration, a = g

Using the equation of motion

$s = ut+\frac{1}{2}at^2$

$2.8 \text{ m} = 0+\dfrac{gt^2}{2}$

$t = \sqrt{\dfrac{5.6}{g}}$

Motion of plastic ball

This has two components: a vertical and a horizontal.

The vertical motion is under gravity.

Considering the vertical motion,

Initial velocity, u = ?

Distance, s = 1.2 m

Acceleration, a = -g (It is going up)

Using the equation of motion

$s = ut+\frac{1}{2}at^2$

$1.2\text{ m} = ut-\frac{1}{2}gt^2$

Substituting the value of t from the previous equation,

$1.2\text{ m} = u\sqrt{\dfrac{5.6}{g}}-\dfrac{1}{2}\times g\times\dfrac{5.6}{g}$

$u\sqrt{\dfrac{5.6}{g}} = 4.0$

Taking g = 9.8 m/s²,

$u = \dfrac{4.0}{0.756} = 5.29 \text{ m/s}$

This is the vertical component of the initial velocity

Considering the horizontal motion which is not accelerated,

horizontal component of the initial velocity is horizontal distance ÷ time.

$u_h = \dfrac{4.4\text{ m}}{0.756\text{ s}} = 5.82\text{ m/s}$

The initial velocity is

$v_i = \sqrt{u^2+u_h^2} = \sqrt{(5.29\text{ m/s})^2+(5.82\text{ m/s})^2} = 7.9 \text{ m/s}$

4 0

3 years ago

Convert the following: 52 miles/hour to meters/second

Komok [63]

Answer:

23.246 metres per second

Explanation:

divide the speed value by 2.237

5 0

3 years ago

A lever is used to lift a heavy rock. The mechanical advantage of the lever is 4 and the lever applies a force of 800 N to the r

Lesechka [4]

The force applied to the lever is 400 N, because the force applied by the lever (800 N) divided by the mechanical advantage of the lever (4) equals
400 N.

(800/4) = 200

7 0

3 years ago