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3 years ago

A negative acceleration means that the speed of the object decreases. What makes this sentene incorrect?

2 answers:

meriva3 years ago

6 0

Negative acceleration can be in two ways. It can be that the object is slowing down or it is accelerating towards another direction. The statement can be correct and wrong. Displacement is also very important whether or not the object is slowing down or moving faster

Sophie [7]3 years ago

4 0

It's not the speed , it's the rate of change of the speed decreases

You might be interested in

A car traveling at 5m/s starts to speed up after 3 seconds its velocity has increased to 11 m/s what is its acceleration

vfiekz [6]

Answer:

a=(v-u)/t

Explanation:

a =(11-5)/3

a= 8/3

a= 2.6 m/s

4 0

2 years ago

In a chemical reaction, molecules of hydrogen gas (H2) react with molecules of oxygen gas (O2) in a sealed reaction chamber to p

11Alexandr11 [23.1K]

Answer:

Option (B) is correct.

Explanation:

Given that the molecules of hydrogen gas ( $H_2$ ) react with molecules of oxygen gas ( $O_2$ ) in a sealed reaction chamber to produce water ( $H_2O$ ).

The governing equation for the reaction is

$2H_2 +O_2 \rightarrow 2H_2O$

From the given, the only fact that can be observed that 2 moles of $H_2$ and 1 mole of $O_2$ reacts to produce 2 moles of $H_2O$ .

As the mass of 1 mole of $H_2 = 2$ grams ... (i)

The mass of 1 mole of $O_2 = 32$ grams ...(ii)

The mass of 1 mole of $H_2O = 18$ grams (iii)

Now, the mass of the reactant = Mass of 2 moles of $H_2$ + mass 1 mole of $O_2$

$= 2 \times 2 + 32$ [ using equations (i) and (ii)]

$=4+32 = 36$ grams.

Mass of the product = Mass of 2 moles of $H_2O$

$=2\times 18$ [ using equations (iii)]

=36 grams

As the mass of reactants = mass of the product.

So, mass is conserved.

Hence, option (B) is correct.

8 0

2 years ago

A small branch is wedged under a 200 kg rock and rests on a smaller object. The smaller object is 2.0 m from the large rock and

Alexxandr [17]

Answer:

$F =326.7 \ N$

$M = 6$

Explanation:

From the question we are told that

The mass of the rock is $m_r = 200 \ kg$

The length of the small object from the rock is $d = 2 \ m$

The length of the small object from the branch $l = 12 \ m$

An image representing this lever set-up is shown on the first uploaded image

Here the small object acts as a fulcrum

The force exerted by the weight of the rock is mathematically evaluated as

$W = m_r * g$

substituting values

$W = 200 * 9.8$

$W = 1960 \ N$

So at equilibrium the sum of the moment about the fulcrum is mathematically represented as

$\sum M_f = F * cos \theta * l - W cos\theta * d = 0$

Here $\theta$ is very small so $cos\theta * l = l$

and $cos\theta * d = d$

Hence

$F * l - W * d = 0$

=> $F = \frac{W * d}{l}$

substituting values

$F = \frac{1960 * 2}{12}$

$F =326.7 \ N$

The mechanical advantage is mathematically evaluated as

$M = \frac{W}{F}$

substituting values

$M = \frac{1960}{326.7}$

$M = 6$

6 0

3 years ago

A 0.095 kg tennis ball is traveling to the right at 40 m/s when it bounces of a wall and travels in the opposite direction it ca

Mashutka [201]

given that

mass of ball = 0.095 kg

initial velocity of ball towards the wall = 40 m/s

final velocity of the ball after it rebound = 30 m/s

now change in momentum is given as

$\Delta P = m(v_f - v_i)$

$\Delta P = 0.095(30 - (-40))$

$\Delta P = 6.65 kg m/s$

So change in momentum will be 6.65 kg m/s

3 0

2 years ago

A wagon is rolling forward on level ground. friction is negligible. the person sitting in the wagon is holding a rock. the total

vladimir2022 [97]

use the equation mv+mv=mv+mv

95.5(.51)= 95.2(X)+ 17.5(.290)

Now solve for X and that should be your answer

you know that if you throw the rock forward then the the same amount of force is applied backwards onto the person throwing the rock so if the force applied to the rock is mass times velocity then find the force for the cart and subtract the carts force forward by the force the rock exerts backwards.

7 0

3 years ago