Answer:
114.19186 m
Explanation:
v = Velocity of girl at bottom = 7.1 m/s
= Coefficient of kinetic friction = 0.045
g = Acceleration due to gravity = 9.81 m/s²
d = Distance
N = Normal force = 783 N
The weight of the sled and girl is considered as the sum of the frictional force and weight
Hence we use the following equation where the kinetic energy and potential energy are conserved
The sled travels 114.19186 m on the level ground before coming to a rest
Answer:
Explanation:
Moment of inertia of wheel = 1/2 x mR² , m is mass and R is radius of wheel
= .5 x 9 x .4²
= .72 kg m²
Torque created on wheel by string = T x r , T is tension and r is radius of wheel .
13 x .4 = 5.2 N m
angular acceleration α = torque / moment of inertia
= 5.2 / .72
= 7.222 rad /s²
a ) final angular speed = α x t , α is angular acceleration , t is time.
= 7.222 x .72
= 5.2 rad /s
b )
θ = 1/2 α t² , θ is angle turned , t is time
= .5 x 7.222 x .72²
= 1.872 rad
average angular speed = θ / t
= 1.872 / .72
= 2.6 rad /s
c )
angle turned = 1.872 rad ( discussed above )
d )
length of string coming off
= angle rotated x radius of wheel
= 1.872 x .4
= .7488 m .
74.88 cm
Answer:
The ball will return to the thrower's hand with a speed of 10 m/s
Explanation:
- what is straight upward motion?
It is the motion when an object is projected upward, it moves in the opposite direction of the force of gravity.
The velocity is negative while the object moves up and positive while it moves downward due to upward motion.
Here,
A ball is thrown straight upward, u = 10 m/s
final velocity since ball momentarily stops at highest point, v= 0 m/s
According to Newton's 3rd equation of motion:
where,
g = acceleration due to gravity = -9.8 m/s²
h = height
substituting the values,
2(-9.8)h = (0)² - (10)²
h = 100 / 19.6
h = 5.10 m/s
Now, we consider downward motion:
2gh = v² - u²
where,
g = 9.8 m/s²
h = height = 5.10 m
v = return velocity of ball
u = 0 m/s
substituting the values,
2(9.8)(5.10 m) = V² - (0)²
V = √(99.96)
V = 9.99 m/s
V ≈ 10 m/s
Hence,
the ball will return to the thrower's hand with a speed of 10 m/s
Learn more about projectile upward motion here:
<u>brainly.com/question/11049671</u>
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Answer:C
Explanation:
Given
weight of object is equal to weight of object
Suppose weight of Planck is W
suppose weight is at distance of x cm from wedge
balancing Torque
i.e. at a distance of 0.25L from the Left end
D = <span>
2.4 g/cm3We learned this in my physics class as well.
</span><span><span>
p = m/v</span></span>
Where:
p = density
m = mass
V = volume
So to find the density you solve 36/16
=2.4
Hope this helped. Have a great day!