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Molodets [167]
3 years ago
14

3. Ms. Johnson can bench press 150 kg from 0.7 m from the ground to 1.5 m above the ground. a. How much weight (not mass) did Ms

. Johnson lift? Put down Givens, Solving For, Equation, Substitution, Answer with Units
b. How much power did she use if she lifts the weights in 10s? Put down Givens, Solving For, Equation, Substitution, Answer with Units
Physics
1 answer:
miss Akunina [59]3 years ago
5 0

Explanation:

a. Given:

m = 150 kg

a = 9.8 m/s²

Solving for: F

Equation: F = ma

Substitution: F = (150 kg) (9.8 m/s²)

Answer: F = 1470 N

b. Given:

y₀ = 0.7 m

y = 1.5 m

F = 1470 N

t = 10 s

Solving for: P

Equation: P = F Δy / Δt

Substitution: P = (1470 N) (1.5 m − 0.7 m) / 10 s

Answer: P = 117.6 W

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Briefly answer the following questions. a) A clock is mounted on the wall. As you look at it, what is the direction of the angul
Lelu [443]

Answer:

Explanation:

a ) The direction of angular velocity vector of second hand will be along the line going into the plane of dial perpendicular to it.

b )  If the angular acceleration of a rigid body is zero, the angular velocity will remain constant.

c )  If another planet the same size as Earth were put into orbit around the Sun along with Earth  the moment of inertia of the system will increase because the mass of the system increases. Moment of inertia depends upon mass and its distribution around the axis.

d ) Increasing the number of blades on a propeller increases the moment of inertia , because both mass and mass distribution around axis of rotation increases.

e ) It is not possible  that  a body has the same moment of inertia for all possible axes because a body can not remain symmetrical about all axes possible. Sphere has same moment of inertia about all axes passing through its centre.

f ) To maximize the moment of inertia of a flywheel while minimizing its weight, the  shape and distribution of mass should be such that maximum mass of the body may be situated at far end of the body from axis of rotation . So flywheel must have thick outer boundaries and this should be

attached with axis with the help of thin rods .

g ) When the body is rotating at the same place , its translational kinetic   energy is zero but its rotational energy can be increased

at the same place.

3 0
3 years ago
A child swings on a playground swing. How many times does the child swing through the swing's equilibrium position during the co
Karolina [17]
<h2>The child swing through the swing's equilibrium position 6 times during the course of 3 periods.</h2>

Explanation:

One period means time taken to complete one revolution.

In case of swings in one period time it travels the same position through two times.

Here we need to find how many times does the child swing through the swing's equilibrium position during the course of 3 period(s) of motion.

For 1 period = 2 times

For 3 periods = 3 x For 1 period

For 3 periods = 3 x 2 times

For 3 periods = 6 times

The child swing through the swing's equilibrium position 6 times during the course of 3 periods.

3 0
3 years ago
Which is an example of action and reaction forces?
Vlad [161]

Hey there!

the answer is

C. a tennis racket striking a tennis ball

Thank you

Best regards

           OFFICIALLYSAVAGE2003

7 0
4 years ago
Read 2 more answers
A projectile has an initial horizontal velocity of 34.0 M/s at the edge of a roof top. Find the horizontal and vertical componen
Sveta_85 [38]

Answer:

v_x=34 m/s

v_y=53.9\ m/s

Explanation:

<u>Horizontal Launch</u>

When an object is thrown horizontally with a speed v from a height h, it describes a curved path ruled by gravity until it eventually hits the ground.

The horizontal component of the velocity is always constant because no acceleration acts in that direction, thus:

vx=v

The vertical component of the velocity changes in time because gravity makes the object fall at increasing speed given by:

v_y=g.t

The horizontal component of the velocity is always the same:

v_x=34 m/s

The vertical component at t=5.5 s is:

v_y=9.8*5.5=53.9

v_y=53.9\ m/s

8 0
3 years ago
Which of these does not depend on a close binary system to occur?
Alinara [238K]

Answer:

B type ii supernova is the right answer

6 0
1 year ago
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