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3 years ago

5

An athlete is working out in the weight room.he steadily holds 50 kilograms above his head for 10 seconds which statement is tru

e about this situation

1 answer:

My name is Ann [436]3 years ago

3 0

The athlete is doing work because he prevents the weight from falling downward

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How does the mass of an object affect the outcome when an unbalanced force acts on it?

Verdich [7]

Answer:

The magnitude of acceleration is reduced.

Explanation:

Force is defined as push or pull

The force is said to be<em> balance force </em>if the force are equal in size but opposite in direction. ie the object does not move or move with constant speed.

The force are to be<em> unbalanced force </em>if the force cause change in motion. ie the object has force greater than zero and has acceleration.

According to <em>Newton second law of motion </em>, acceleration depends on force acting on the object and mass of object.

F=ma

a= $\frac{F}{m}$

When unbalanced force act on the mass of object it reduces magnitude of acceleration without changing the direction.

6 0

3 years ago

At an instant a traffic light turns green an automobile that has been waiting at an intersection of the road accelerates with 5m

joja [24]

1) The car overtakes the truck at a distance of 160 m far from the intersection.

2) The velocity of the car is 40 m/s

Explanation:

1)

The car is travelling with a constant acceleration starting from rest, so its position at time t (measured taking the intersection as the origin) is given by

$x_c(t) = \frac{1}{2}at^2$

where

$a=5 m/s^2$ is the acceleration

t is the time

On the other hand, the truck is travelling at a constant velocity, therefore its position at time t is given by

$x_t(t) = vt$

where

v = 20 m/s is the velocity of the truck

t is the time

The car overtakes the truck when the two positions are the same, so when

$x_c(t) = x_t(t)\\\frac{1}{2}at^2 = vt\\t=\frac{2v}{a}=\frac{2(20)}{5}=8 s$

So, after a time of 8 seconds. Therefore, the distance covered by the car during this time is

$x_c(8) = \frac{1}{2}(5)(8)^2=160 m$

So, the car overtakes the truck 160 m far from the intersection.

2)

The motion of the car is a uniformly accelerated motion, so the velocity of the car at time t is given by the suvat equation

$v=u+at$

where

v is the velocity at time t

u is the initial velocity

a is the acceleration

For the car in this problem, we have:

u = 0 (it starts from rest)

$a=5 m/s^2$

And we know that the car overtakes the truck when

t = 8 s

Substituting into the equation,

$v=0+(5)(8)=40 m/s$

Learn more about accelerated motion:

brainly.com/question/9527152

brainly.com/question/11181826

brainly.com/question/2506873

brainly.com/question/2562700

#LearnwithBrainly

8 0

2 years ago

Consider a balloon of mass 0.030kg being inflated with a gas of density 0.54kg/m. What will be the volume of the balloon when it

Nonamiya [84]

the weight of the balloon is .030 * 10 = 0.3 N

the weight of the gas of volume v is 0.54*10 N

The lifting force of a volume of v m³ of displaced air is 1.29v N

so, we need

1.29*10*v = 0.3 + 0.54*10*v

or

1.29v = 0.03+0.54v

7 0

1 year ago

A dockworker applies a constant horizontal force of 90.0 N to a block of ice on a smooth horizontal floor. The frictional force

Oliga [24]

Answer:

The mass of the ice block is equal to 70.15 kg

Explanation:

The data for this exercise are as follows:

F=90 N

insignificant friction force

x=13 m

t=4.5 s

m=?

applying the equation of rectilinear motion we have:

x = xo + vot + at^2/2

where xo = initial distance =0

vo=initial velocity = 0

a is the acceleration

therefore the equation is:

x = at^2/2

Clearing a:

a=2x/t^2=(2x13)/(4.5^2)=1.283 m/s^2

we use Newton's second law to calculate the mass of the ice block:

F=ma

m=F/a = 90/1.283=70.15 kg

6 0

3 years ago

Read 2 more answers

Which telescope would be better viewing a faint, distant star? Why?

grin007 [14]

Reflecting telescope. Reflecting telescopes tend to have larger objective (due to the use of mirrors, mirrors are a lot cheaper than lenses) and have the ability to collect more light, while refracting telescopes are limited to objective lenses with smaller diameters due to their structural limitations (chromatic abbreviation, for example). Therefore, reflecting telescopes should be better at viewing faint distant stars

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2 years ago